Please do not destroy or throv away this publication. JTyou have no further use 

for it write to the Geological Survey at Washington andiaskf^r a frank to return it

DEPARTMENT OF THE INTERIOR

Hubert Work, Secretary

U. 8. GEOLOGICAL SURVEY 

George Otis Smith, Director

WATER-SUPPLY PAPER 577

PLANTS AS INDICATORS OF GROUND WATEB

BY

OSCAR EDWARD MEINZER

UNITED STATES

GOVERNMENT PRINTING OFFICE

WASHINGTON

1927
DEPARTMENT OF THE INTERIOR

Hubert Work, Secretary

U. S. GEOLOGICAL SURVEY 

Georgte Otis Smith, Director

Water-Supply Paper 577

PLANTS AS INDICATORS OF GROUND WATER

BY

OSCAR E}DWARD MEINZER

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON

1927
ADDITIONAL COPIES

OF THIS PUBLICATION MAY BE PROCUBEDTFEOM

THE SUPEEINTENDENT OF DOCUMENTS

U.S.GOVEENMENT PEINTING\>FFICE

WASHINGTON, D. C.

AX

25 CENTS PER COPY
CONTENTS

Introduction ______________________ - 1

Plants that habitually feed on ground water 1

Evidences of the ground-water habit 2

History of the subject 8

Questions that deserve further study 14

Acknowledgments __ _ IS

Principal species of plants that habitually feed on ground water 15

Arrangement of species _ _ 15

Bushes; sedges, and cat-tails. _______ 16

Reeds and cane__ _ _ _ _____ _ ___ 17

Wild rye ______________ _ ___ _ _ ____________ 17

Salt grass _______________ _ ________ _______ 19

Sacaton ________________ ___ ___ 23

Pickleweed, samphire, seepweed, and other succulent salt-resistant

plants ________ ________ _ _ __ _ _ 25

Yerba mansa __ _ _____ ___ __ ____ _ _ __ _ 29

Rabbit brush and related species __________ _ _ 29

Arrow weed, batamote, and jacate __________ _ _ _ 31

Saltbushes __________________________________ 32

Greasewood ______ __ ___ __ __ ________ _ ___ _ _ 37

" Mesquite and associated plants ________________ _ ____ 42

Alfalfa _____________________________________ 54

Willow _____________________________________ 58

Desert willow- _ ___ _____ _ _______________ 57

Oottonwood and other poplars ___________________ _ ___ 58 

Buffalo berry, elderberry, blackberry, gooseberry, and hackberry

bushes, shrubby cinquefoil, and wild roses __________ __ 59

Washington palm and other palms __________________ 00

Forest trees ________ _ ________________________ 61

Prominent desert plants that do not habitually feed on ground water 65

Relation of plants that feed on ground water to other groups _______ 67

Relation to plants that live in water ________________ , _ 67

Relation to salt-resistant plants ______________ _ ______ 68

Relation to drought-resistant plants __ _ ________________ 70

Relation to normal plants of humid regions ______________ 71

Talne of plants as indicators of ground-water conditions __________ 72

Occurrence of ground water __ __ __ ____ _ ____ __ ______ 72

Depth to the water table. _______ ___ _ ____ 74

Quality of ground water- ______ ____ __ _______ _________ 77

Quantity of ground water- __________ ______ __ 82 

Relation of transpiration of ground-water plants to water-supply

projects ___ ___ , ________________ _ __ 82

Analysis of the problem of quantity of water transpired ___ 82

The area factor________ _ ___ ^ _________________ 82

The rate factor. _ _ ___ _ __ _ ____________ 83

' m
IV CONTENTS

Value of plants as indicators of ground-water conditions Continued.

Quantity of ground water Continued. i»age

Relation of rate of transpiration to kind of plant_____ ___ 84

Relation of rate to depth of water table______________ 85

Relation of rate to evaporativity_______..__________ 86

Relation of rate to quantity of dry matter___________ 87

Development of ground-water plants of economic value_________ 88

The problem___________________________________ 88

Alfalfa as a ground-water plant, by Walter N. White________ 89

Index___________________________________. _____ 93

ILLUSTRATIONS

Page

PLATE 1. Upper Valley of Birch Creek, in the Toyabe Mountains, Nev., 

showing area of shallow ground water as indicated by the 

vegetation ____________________________ 6

2. Mohave River Valley at Camp Cady, Calif., showing zones of

vegetation due to different depths to ground water_____ 7

3. A, Area of shallow ground water in southeastern California, 

with growth of salt grass and scattered mesquite; B, Cut 

bank of Santa Cruz River near Tucson, Ariz., showing the 

deep roots of mesquite_________ ___ __ __ 40

4. A, Clump of mesquite showing roots reaching down toward 

water table; B, Mesquite at foot of cliff, showing contrast 

with desert where it supports only sparse growth of vegetation that does not feed on ground water; C, Greasewood occupying wind-built mound on the otherwise barren playa of Big 

Smoky Valley, Nev______________________________ 40

5. A, Vegetation of the mesquite zone surrounding the area of 

shallow ground water in Sulphur Spring Valley, Ariz.; 

B, Clumps of mesquite in Mohave Desert, near Daggett, 

Calif., indicating ground water within reach of the mesquite 

roots___________________________ * _ 40

6. A, Mohave River valley near Barstow, Calif., showing mesquite 

and poplar trees supported by ground water; B, Running 

mesquite in area of shallow ground water near Shaver well, 

in the desert region of southeastern California 41

7. Mohave River valley near Yermo, Calif., showing dunes on both

sides, due largely to mesquite that feeds on ground water 54

8. A, Alfalfa raised in sec. 31, T. 28 S., R. 10 W., near Milford, 

Utah, without irrigation; B, Thicket of birch trees that feed 

on ground water at the mouth of Santa Fe Canyon, Big Smoky 

Valley, Nev________________ _ 54

9. A, Willow trees at Hidden Springs, in the desert region of southeastern California; B, Willow tree at Leach Spring, in the 

desert region of southeastern California 54 

10. A, Zone of trees that feed on ground water in Mohave Valley, 

Calif., in contrast with the desert area that does not support 

ground-water plants; B, Grove of cottonwood trees that indicate an area of shallow ground water in the Salton Sea 

region, Calif____ _ - 5*
ILLUSTRATIONS V

Page.

PLATE 11. A, Seven Palms, a spring locality in the desert region of south

eastern California; B, Palm, cottonwood, and mesquite trees

* in area of shallow ground water at Corn Springs, in the

desert region of southeastern California-___ 54 

12. A, Large palm trees in area of shallow ground water in the 

arid region near Guantanamo Naval Station, Cuba; B, Grove 

of palm trees that indicate shallow ground water in an arid 

part of southern Cuba__ _ _ 55 

FIGURE 1. Profile across Mohave River valley at Camp Cady, Calif.,

showing distribution of ground-water plants- 6

2. Salt grass (Distichlis spicata) _________ __> .,__.. _ 2Q

3. Map of Independence district of Owens VaJley, Calif., showing

area of ground-water discharge________________ 21

4. Alkali sacaton or tussock grass (Sporobolus airoides) ________ 24

5. Pickleweed (Allenrolfea octidentalis) .._________________ 26

6. Map of a part of the east slope of "Tularosa Basin, N. Mex., 

showing areas in which mesquite is the dominant plant and 

their relation to ground water___________________ 34

7. Map of a part of the west slope of Tularosa Basin, N. Mex., 

showing belts of vegetat'on and their relation to ground 

water.____________..__________________ 35

8. Big greasewood (Sarcobatus vermteulatus) _________________ 38

9. Map of a part of B'g Smoky Valley, Nev., showing zones of

vegetation ________________________________ 40

10. Map of a part of S'teptoe Valley, Nev., showing zones of vegetation and their relation to the water table_______ _ 42

11. Map of a locality near the Desert Laboratory, Tucson, Ariz., 

showing approximate distribution of mesquite (Prosopis 

velutina) ____________________________ 44

12. Map of a part of Sulphur Spring Valley, Ariz., showing zones

of vegetation and their relation to the water table 47

13. Map of a part of Playas Valley, N. Mex., showing zones of

vegetation and their relation to ground water_______ 50

14. Sections showing relation of mesquite to the water table in

the Salton Sea region, Calif___________________ 53

15. Diagram of the root system of an alfalfa plant in Escalante

Valley, Utah____________________________ 91

PLANTS AS INDICATORS OF GROUND WATER

By OSCAR EDWARD MEINZER

INTRODUCTION

PLANTS THAT HABITUALLY FEED ON GROUND WATER

Perhaps the most outstanding feature of the flora of the desert 

is its relation or lack of relation to the water table. On the one 

hand are the plants which are adapted to extreme economy of water, 

which depend on the rains that occur at long intervals for their 

scanty water supplies, and which during prolonged periods of 

drought maintain themselves in a nearly dormant condition. These 

plants are known as xerophytes (from Greek roots meaning "dry 

plant"). On the other hand are the plants that habitually grow 

where they can send their roots down to tl^e water table or to the 

capillary fringe immediately overlying the water table and are thus 

able to obtain a perennial and secure supply of water. These plants 

have been called phreatophytes.1 The term is obtained from two 

Greek roots and means a " well plant." Such a plant is literally a 

natural well with pumping equipment, lifting water from the zone 

of saturation.

The terms " ground water," " zone of saturation," " water table," 

and " capillary fringe " are used in this paper as previously defined 

by the writer.2 The term " ground water " is used by the writer 

and, so far as could be determined, by the authorities that are

1 Meinzer, O. B., Outline of ground-water hydrology, with definitions: U. S. Geol. Survey Water-Supply Paper 494, p. 55, 1923. In so far as the writer Is informed, the term

 ' phreatophyte " was first used by him in a mimeographed edition of the paper which was 

later issued in revised form as Water-Supply Paper 494. See also Meinzer, O. E., Plants as 

indicators of ground water: Washington Acad. Sd. Jour., vol. 16, pp. 553>-564, 1926. The 

principal ecologic groups of plants that have been recognized by botanists are hydrophytes, 

which grow in water or at least with their roots under water 5 the halophytes, which can

 endure large amounts of salt or alkali in the soil water on which they live; the xerophytes, 

which are able to survive on very small and irregular supplies of water; and the mesophytes, which are not adapted to endure any of these extremes. In proposing the name 

phreatophyte the writer did not imply that this group should find a separate place in the

 old classification, but rather believed that it would overlap some of the other groups. 

The term " helophyte " has been used for marsh plants, which are more or less intermediate between hydrophytes and nresophytes, but this term could not be used to designate the 

phreatophytes without violating its past usage and introducing much confusion. (See, 

for example, Warming, Bugen, Oecology of plants, p. 185, Oxford, 1909.)

2 Op. cit. (Water-Supply Paper 494), pp. 21, 22, 26.
2 PLANTS AS INDICATORS OF GROUND WATER

quoted, to designate the water in the zone of saturation that is, 

below the water table.

The plants that feed on ground water form a fairly definite and 

well-recognized group in the desert regions and a much less definite 

group in the humid regions, where water supplies from other sources 

are more abundant. In the most arid regions the plants that feed 

on ground water stand in sharp contrast to the desert plants that 

do not utilize water from the zone of saturation. However, in passing into less arid and then into more and more humid regions the 

control of the water table becomes progressively less rigid, until 

even the plants that have been most dependent on it are able to 

live in all sorts of situations entirely beyond its reach.

Even in the desert regions many if not all ground-water species 

will spread more or less to localities where their roots do not reach 

the water table, such as irrigation ditches, irrigated fields, streams, 

and dry washes that are far above the water table, or even alluvial 

slopes and hillsides. It is also true that plants of species that do 

not habitually utilize ground water may do so under certain circumstances and may flourish, at least for a time, on such a water supply. 

Moreover, there is not always a wholly definite distinction between 

ground water and other soil moisture, because of the existence 

of a great variety of perched and temporary water tables and of 

gravity water that may be in transit from the surface to the water 

table. However, these exceptions and complicating conditions do 

not alter .the important fact that there .are certain plant species 

which habitually feed on ground water and others which do not, 

and that in the arid regions there is a very real and conspicuous 

distinction between these two groups. This distinction is, indeed, 

often more real than appears on casual observation, for some of the 

ground-water plants are closely related to species of the other group 

which resemble them, and frequently plants of one of these related 

species growing in dry localities are mistaken for stunted individuals 

of the ground-water species. Moreover, in many places clumps of 

a ground-water species growing outside of the recognized shallowwater belts do not form-exceptions to the rule but instead faithfully 

indicate the presence of ground water near the surface where it would 

otherwise not be suspected.

EVIDENCES OP THE GBOtTND-WATER HABIT

The evidence that plants of certain species possess the groundwater habit or adaptation whereas those of other species do not 

possess it may be grouped as follows: (1) Observations of the root 

habit of different species, showing their relation or absence of relation to the water table and showing the ability of some species to
INTRODUCTION O

send roots to great depths; (2) experiments with certain species in 

which the quantities of water they absorb from the zone of saturation are measured or the effects of their growth in lowering the 

water table are recorded; (3) determinations of soil moisture during 

dry periods in an arid region, showing that certain species grow 

chiefly or exclusively with their roots penetrating into soil which 

contains moisture that could not have been supplied by rains but 

must have risen from the zone of saturation, whereas other species 

are found chiefly or exclusively with their roots in dry soil that is 

not moistened by ground water; (4) observations in arid regions of 

the relation or absence of relation of the period of growth of different species to the rainy season, showing that certain species (commonly growing where the ground water is beyond the reach of the 

plant roots) become dormant after the supply of soil moisture 

derived from the rains has been exhausted, whereas other species 

(growing where the ground water is within reach) continue to grow 

actively throughout the summer; and (5) observations in arid 

regions of the depth to the water table, showing that certain species 

are confined almost completely to areas with specific depth limits, 

whereas others show no relation to the water table and may grow 

where the water table is at a great depth or where ground water is 

entirely absent.

1. There are widely scattered data as to the depths and habits of 

the roots of plants that utilize ground water, in contrast to those 

that do not, though most of these data are not so definite as could be 

desired. A few striking facts as to the depths to which the roots 

may go for water are given elsewhere in this paper. (See especially 

fig. 15, p. 91.) A study of the subject, especially with reference to 

forest trees, has been made by Cannon,3 who makes the following 

statement:

It is now well established, at least for a portion of the Southwest, that there 

may be a very intimate relation between the occurrence of certain species of 

trees and the character of their roots, having regard to the depth at which 

perennial water may be found. Here trees occur along streamways, while the 

near-by upland may be treeless. The humidity of the two areas may not be 

very unlike, nor the rainfall, nor yet the temperature. The great difference, 

which is often striking, lies mainly in the soil conditions, particularly with 

regard to the depth to the ground water. On the bottoms the water table lies 

within reach of the roots of trees, while on the more elevated land it is far 

below them. * * *

The problems which deal with the presence of trees are primarily physiological and have mainly to do with the absorption and conservation of water. 

Each of these capacities varies with the species. Of the root relations, that of

8 Cannon, W. A., The root habits of desert plants: Carnegie last. Washington Pub. 131, 

1911; Some relations between root characters, ground water, and species distribution: 

Science, new ser., vol. 37, pp. 420-423, 1923; Tree distribution in central California: Pop. 

Sci. Monthly, vol. 85, pp. 417-424, 1914.
4 PLANTS AS INDIGATOES OF GEOTJND WATEE

the root-and-water table is of prime importance, owing to the fact that the 

soil horizon tapped by the roots of trees derives by capillarity, from the level 

of the ground water, its perennial supply of moisture.

Striking examples have been observed by the writer of the depths 

to which the roots of trees of a certain species will go for a reliable 

supply of water in one of the rugged limestone regions of Cuba. In 

spite of the heavy precipitation in this region the trees in exposed 

localities have great difficulty in obtaining enough water, because of 

the lack of soil and the cavernous character of the limestone. Wherever possible the roots descend through crevices or over escarpments 

of the rocks, and in one place they were seen extending vertically 

down over a sheer cliff about 100 feet into a perennial stream where 

it emerges from a cavern. These long roots have functional rootlets 

only at their lower ends, where they dip into the water.

2. The experiments which definitely demonstrate that plants of 

certain species feed on ground water are of two kinds. In one plants 

are grown in tanks that are filled with soil in which a water table is 

maintained at a certain level by adding measured quantities of 

water from below, to replace the water that is removed by the 

transpiration of the plants or by both transpiration and evaporation, 

as in the experiments by Lee * with salt grass and recently by Walter 

N. White, of the Geological Survey, with greasewood, salt grass, and 

alfalfa. In the other a record of the fluctuations of the water table 

is obtained by means of a water-stage recorder installed in a well in 

a tract where the plants under investigation are growing naturally. 

This method was devised by G. E. P. Smith,5 who demonstrated that 

the water table under a forest of mesquite trees declines during 

periods of growth but not at night, on cloudy days, or at times when 

the mesquite trees shed their leaves. Similar records have been 

obtained by Smith on tracts of cottonwood, salt grass, and sacaton, 

and recently by Mr. White on unirrigated alfalfa in the desert and 

on salt grass and greasewood.

3. Determinations of soil moisture which show that certain species 

utilize ground water during the dry periods while others do not 

were made in connection with the investigation of the indicator 

significance of vegetation in Tooele Valley, Utah.6 The following 

quotation from the Tooele Valley report summarizes the contrasting 

results for greasewood, a well-known ground-water plant, and shad 

scale, a very common desert plant which is not dependent on ground 

water :

It is significant that moisture available for the growth of plants [excess of 

moisture content over wilting coefficient] was present in considerable quantity

* Lee, C. H., An intensive study of the water resources of a part of Owens Valley, Calif, i 

U. S. Geol. Survey Water-Supply Paper 294, pp. 53-60, 1912.

8 Personal communication.

9 Kearney, T. H., and others, Indicator significance of vegetation in Tooele Valley, 

Utah: Jour. Agr. Research, vol. 1, pp. 365-417, 1914.
INTRODUCTION O

during the months of June and July in all but the surface foot in the greasewood-shad scale association, while in the shad scale association during the same 

months there was a marked deficit of available water to a depth of 4 feet. 

The relatively high moisture content is correlated with the relatively slight 

elevation above the level of water in the lake and with a consequently high 

ground-water table. * * *

Greasewood prefers an ample and permanent supply of moisture within reach 

of its roots, and its strong, deeply penetrating taproot enables it to reach 

moisture in places where the surface soil is dry and the ground-water table 

is at a considerable depth. * * * Shad scale, on the other hand, does not 

thrive with its roots in wet soil, and its presence is usually a reliable indication 

that at least the surface foot is dry during the greater part of the summer.

4. The fact that certain species which utilize ground water grow 

throughout the summer while other species are dormant except in 

the rainy season is a matter of common observation. It is summed 

up as follows in the Tooele Valley report: 7

In those parts of the valley where the ground water is beyond the reach 

of the plant roots the vegetation becomes dormant after the moisture stored in 

the soil by the winter and spring rains has been exhausted. Herbaceous plants 

ripen and die, at least to the ground, while the woody species, losing much 

of their foliage and reducing their transpiration to a minimum, enter a resting condition which is nearly as complete as that which is brought about by 

the low temperatures ot winter. * * * In the lower part of the valley, 

where the ground-water table is high and the soil is moist throughout the 

summer nearly or quite to the surface, active growth continues until it is 

terminated by frosts.

For the same reason alfalfa, which has adaptations for utilizing 

ground water, will, if well established in an area of shallow water, 

continue to grow through the driest season when other field crops 

that do not have such adaptations utterly perish.

Observations made by Douglass 8 on the relation between tree rings 

and ground water give interesting evidence of the ground-water 

habit in some trees and of a difference between various species of 

trees in this respect, as is shown by the following statement: 9

It was found that dry-climate trees which grew in basins with a large and 

constant water supply, and this refers especially to the Sequoias, usually produced rings without much change in size from year to year. This character 

of ring is called "complacent." The opposite character is the "sensitive" 

ring, where a decided variation is shown from year to year. Sensitive trees 

grow on the higher elevations, where the water supply is not reliable and 

the tree must depend almost entirely on the precipitation during each year. 

Such trees grow near the tops of ridges or are otherwise separated from any 

collection of water in the ground. In case of the basin trees one could be 

sure that a ring was produced every year, but owing to the lack of individualT Kearney, T. H., and others, op. cit., p. 370.

8 Donglass, A. B., Some aspects of the ase of the annual rings of trees in climatic 

study: Smithsonian Inst. Kept, for 1922 (Pub. 2731), pp. 223-239, 1924; Some topographic and climatic characters in the annual rings of the yellow pines and Sequoias of, 

the Southwest: Am. Philos. Soc. Proc., vol. 61, pp. 117-122, 1922; Climatic cycles and 

tree growth: Carnegie Inst. Washington Pub. 289, 1919.

 Smithsonian Inst. Kept, for 1922, pp. 230, 231, 1924.
t> PLANTS AS INDICATORS OF GROUND WATER

ity in the rings for certain years it was difficult to compare trees together and 

produce reliable data. In case of the sensitive trees growing in the uplands 

there was so much individuality in the rings that nearly all of the trees could 

be dated with perfect reliability, but in extreme cases the omission of rings 

in a number of trees required special study. * * * Trees growing in the 

dry climate of Arizona at an altitude where they have the utmost difficulty in 

getting water to prolong life become extraordinarily sensitive. In the same 

tree one finds some rings several millimeters across and others microscopic in 

size or even absent. * * * The great sensitiveness of the yellow pines as 

compared with the best Sequoias is evident in any brief comparison of dated 

specimens.

5. The numerous observations made by the writer and others, as 

cited in this paper, of the relation between the depth to the water 

table and the occurrence of certain plant species in arid regions give 

convincing and abundant evidence of the ground-water habit in some 

species and its absence in others. In the arid regions of the western 

part of the United States tracts of shallow ground water occur in 

three principal situations (1) in the canyons and other localities in

N. S.

Poplar, willow, Saltgrass,mes- Salt£rass Ordinary desert

Feet Ordinary desert andmesquite quite,andwillow and mesquite ' ' "

ao-TO^g6*31'0" ' " "

20-

Horizontal scale

2,000 FEET

FIGURE 1. Profile across Mohave River valley at Camp Cady, Calif., showing 

distribution of ground-water plants. After D. G. Thompson. (See pi. 2.)

the mountains where the water is held up by impermeable bedrock 

near the surface, (2) in the lowest parts of the principal basins or 

inter montane valleys, and (3) at certain intermediate points where 

barriers to the ground water occur. The largest areas of plants that 

feed on ground water are in the valley lowlands, but distinctive 

plants of this group also grow in higher tracts where they are reliable 

indicators of ground water. The native plants found in these tracts 

of shallow ground water are not the same species as grow elsewhere 

in the desert but consist of a few distinctive species which dominate 

the shallow-water tracts and are absent or |have only very sparse 

growth in other parts of the desert region wfhere the water table is 

not near the surface. (See pis. 1 and 2 and fi£. 1.)

As a rule in the interior lowland of a Hrge desert basin these 

ground-water species occupy a zone of shallow ground water surrounding a central playa that is virtually destitute of all vegetation. 

The unfavorable conditions that make the blaya barren need not 

be discussed here further than to say that sonlie of the worst features 

are the alkaline character of the soil and i4 large parts its clayey
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 1

***c*$g''&-^,^e:&lls^^r ^£.:jf-. <->' ' ; fe*' ! /-l

<*;c . *: B -i ,_".*'-''*»1-J*

UPPER VALLEY OF BIRCH CREEK, IN THE TOYABE MOUNTAINS, NEV., SHOWING AREA OF SHALLOW GROUND WATER AS INDICATED BY

THE VEGETATION
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 2

MOHAVE RIVER VALLEY AT CAMP CADY, CALIF., SHOWING ZONES OF VEGETATION DUE TO DIFFERENT DEPTHS TO GROUND WATER

Desert brush in the foreground, zone of salt grass supplied by ground water on the lowland back of the desert brush, and zone of poplar, willow, and mesquite on the flood plain back of the salt grass zone. (See fig. 1.) Photograph by D. G. Thompson
INTRODUCTION 7

texture, which renders it impermeable to ground water and results 

in violent variations of moisture conditions, ranging from extreme 

aridity to complete submergence in times of heavy freshets.

The zone of shallow ground water surrounding the playa can generally be subdivided into several concentric belts of vegetation, in each 

of which one or more ground-water species is dominant. The successive belts vary in texture and alkalinity of soil as well as in depth 

to the water table. These differences hi the soil have an important modifying influence on the type of vegetation and on the 

limits of the successive belts, and they have received much more 

attention than the ground-water conditions with respect to their 

effect on vegetation. However, the main factor in the control of 

the vegetation over the area of shallow ground water is the depth 

to the water table. This conclusion is definitely proved by the 

existence of otherwise similar basins which, on account of subterranean leakage, do not have shallow ground water in their interior lowlands. In these basins there may be a barren central 

playa with clayey, alkaline soil, surrounded by belts of soil having 

essentially the same texture as that of the soil in the basins that 

have shallow water, yet the familiar ground-water plants are essentially absent and the ordinary desert species extend to the margins 

of the playa. Doubtless there are some differences in the amount 

and distribution of the alkali in the soil resulting from the absence 

of shallow ground water, but in view of the characteristic growth 

of ground-water plants in many well-drained areas of shallow 

ground water it is certain that the absence of these species in the 

basins having deep ground water is not due to a difference in soil 

alkali.

Good examples of desert basins that do not have shallow ground 

water are Coal Valley, Nev., described by Carpenter,10 and Alkali 

Spring Valley, Nev., described by the writer.11 In Coal Valley no 

water was found in a well drilled to a level 200 feet below the playa, 

and drought-resistant plants, such as shadscale, extend to the edge 

of the playa. In Alkali Spring Valley the water in a dug well at 

the edge of the playa was found to stand 43y2 feet below the surface, 

and no ground-water plants were found except greasewood, which 

may go to this depth for ground water. These basins are in striking 

contrast to the numerous basins in the same region that have areas of 

shallow ground water with their distinctive vegetation as, for example, Big Smoky Valley, Nev.12 

______________i___________________________

10 Carpenter, Bverett, Ground water in southeastern Nevada: U. S. Geol. Survey WaterSupply Paper 365, pp. 68, 69, 1915.

11 Meinzer, O. B., Geology and water resources of Big Smoky, Clayton, and Alkali 

Spring Valleys, Nev.: TJ. S. Gegl.. Survey Water-Supply Paper 423, pp. 148-150, 1917.

12 Idem, pp. 86-104.
8 PLANTS AS INDICATOBS OF GBOITND WATER

In appraising the evidence that certain desert plants possess the 

ground-water habit and others do; not, it should be remembered that 

the several lines of evidence are mutually corroborative and together 

bear much more weight than any one of them, because they all agree 

in selecting the same species as ground-water plants.

HISTORY OF THE SUBJECT

As might be surmised, the subject of plants as indicators of ground 

water is by no means'a new one. Vitruvius,18 a Roman architect and 

engineer, who lived about the time of Christ and who is credited with 

being the first writer to advocate the modern theory of the origin of 

ground water, makes the following statement on the subject:

Besides these there are other indications of places where water can be 

found namely, the presence of small rushes, willows which are not planted, 

alder trees, vitex, reeds, ivy, and all other such plants which occur and thrive 

only in places where there is water. One must not rely on these plants, however, if they occur in marshes, wjiieh, being lower than the surrounding country, 

receive and collect and for some time retain rain waters that fall on the near-by 

fields in winter; but if these plants occur naturally in places that are not 

marshes, one can seek for water in these places. [Translated from Paramelle.]

Somewhat similar statements are found in the writings of Pliny,14 

in the first century A. D., who virtually quoted Vitruvius, and in 

those of Cassiodorus, in the sixth century, who obtained his ideas 

largely from a professional water finder who came to Rome from the 

arid regions of Africa.

Paramelle cites an article in the " Globe " of November 4, 1848, 

which discusses briefly the value of certain trees and smaller plants 

for locating ground water. Paramelle himself, while recognizing 

the relation between certain types of vegetation and the occurrence 

of ground water, did not regard the vegetation as ef practical value 

in locating ground-water supplies, as is shown by the following 

quotation from his well-known book on ground water,15 the first 

edition of which appeared in 1856:

When, the thalweg of a valley is uncultivated and one sees there growing 

naturally willows, poplars, alders, osiers, rushes, reeds, wild mint, silver weed, 

ground ivy, and other water-loving trees or plants, one should presume that 

the course of water [water table?] is not deep in that place. However, as 

these kinds of plants thrive in all humid terranes they can only serve to 

indicate the presence of ground water in so far a.s they are on a thalweg or 

at the bottom of a hollow. Pliny himself had already observed that the search

M Vitruvius Pollio, Marcus, De architecture, quoted by Paramelle, Abb6, I/art dedecouvrir les sources, 4th ed., p. S96, Paris, 1896.

« Naturalis historia, book 81. (First published in Latin in Vienna in 1469. See " The 

natural history of Pliny" translated by John Bostock and H. T. Riley, vol. 5, p. 489, 

London, 1856.)

16 Paramelle, Abb6, op cit., p. 148.
INTRODUCTION 9

for springs by inspection of certain plants which thrive only in humid places 

is not very safe, and he calls these signs erroneous indications (augurlum 

fallax). [Translated.]

The subject was treated more thoroughly in a publication by 

Amy 16 in 1861. His statements in this regard are evidently based 

on his own observations and appear to be reasonably accurate, 

although he may have overestimated the practical value of vegetation for finding ground water. He suggests the possibility also of 

using vegetation as an indicator of depth to and quality of ground 

water, but calls attention to the facts that the indications vary from 

place to place with differences in soil and topography and that vegetation and other surface indications do not show ground water 

where it lies at considerable depth. He gives the scientific names 

of numerous species of plants that indicate ground water. These 

species belong to 14 different families or orders and include birches, 

alders, willows, and poplars, and also sedges, rushes, cat-tails, and 

grasses, among which he mentions reed grass (Phragmites).

Vitruvius and the other writers above mentioned discussed this 

subject in connection with other and even less tangible methods of 

locating ground water, such as color and dampness of the soil, mists 

rising from the ground early in the morning, and sponges becoming 

moist when placed in shallow holes in the ground. Obviously all 

this borders closely on divining, or water witching, and it is greatly 

to the credit of Vitruviua, Pliny, and Cassiodorus that none of these 

ancient writers recognized divining or any other magical method 

for locating ground water.17 Although the means suggested by 

Vitruvius as aids in finding ground water may not have had much 

practical value in the relatively humid country in which he lived, 

yet they were obviously based on outdoor observations and were 

serious efforts to discover sound and practicable methods at a time 

when the science of geology was still a complete blank.

The foregoing review shows that the study of plants as indicators 

of ground water has made very little progress in European countries. Most of the French and German treatises on ground water 

either do not mention the subject at all or else dispose of it very 

briefly, except a book by Mager,18 which not only treats this subject 

at length but also champions the divining rod and other devices. 

The reason for this neglect of the subject by European hydrologists 

is not hard to find it is simply because the subject does not have

M Amy, F., Voyages d'un. hydroscope, ou 1'art de dgcouvrir les sources, Paris, 1861.

17 Raymond, R. W., The divining rod: Am. Inst. Min. Bng. Trans., vol. 11, pp. 415-416, 

1883; U. S. Geol. Survey Mineral Resources, 1882, ?p. 610-626, 1883.

18 Mager, Henrl, Les moyens de de'couvrir les eaux souterraines et de les utillser, pp. 

310-319, Paris, 1912.
10 PLANTS AS INDICATORS OF GEOUND WATEK

and can not be made to have much scientific or practical importance 

in humid regions. It is significant in this connection that Cassiodorus became interested in the subject through an " aquilege " who 

came to the court of Theodoric from Africa. "Because of the 

great aridity of the terranes of his country," wrote Cassiodorus, 

" the art of discovering springs is there cultivated with the greatest 

care."

Eeferences to plants that depend on ground water are found in 

many publications relating to arid regions in foreign countries, but 

no systematic search of this literature was made in connection with 

the present investigation. In so far as the writer knows, no comprehensive study of the subject has been made anywhere outside the 

United States. In describing the desert region of Southwest Africa, 

Wagner 19 makes the following statements:

Trees and plants sometimes afford invaluable assistance [in locating successful wells], the position of master joints or of belts of fissured or decomposed rock, along which underground water percolates, being not infrequently 

indicated at the surface by lines of trees or shrubs, known as " aars." One 

of the most reliable indicators of the existence of water below such aars is 

the Acacia Jwrrida (sweet thorn). Other trees and plants which betray the 

presence of ground water at shallow depths are the ebony tree (Euclea 

pseudebenus), the karree tree (Rhns lancea), the tamarisk (Tamafist awstro®- 

frican§), and the inkbush (Swaeda frutfoosa). In the Namib the narra bush 

(Acanthoslcyos horrida,) is the best indicator.

The desert region of the United States has been estimated to cover . 

about half a million square miles, or about one-sixth of the entire 

area of the country.20 In this region the relation of the native vegetation to ground water is a subject of great scientific and practical 

importance. For many years the region has received much attention from both hydrologists and botanists. It is therefore surprising that this subject should have received but little thorough systematic study in the desert region of the United States and should 

be covered by only a meager and unsatisfactory literature. The 

explanation probably lies in the fact that the subject is in the border 

land between hydrology and botany and has not been preempted by 

workers in either science. The ground-water geologists who have 

worked in the region, realizing their lack of training in botany, have 

avoided getting very deeply involved in the subject; on the other 

hand, the botanists who have worked in the region, unfamiliar with 

the principles of ground-water hydrology, have for the most part

19 Wagner, P. A., The geology and mineral industry of Southwest Africa: South Africa 

Geol. Survey Mem. 7, pp. 22, 116, 1916.

20 Meinzer, O. B., Routes to desert "watering places in California and Arizona: U. S 

Geol. Survey Water-Supply Paper 490-A, p. I, 1920.
INTKODUCTION 11

failed to realize the significance of the subject or have purposely 

avoided going so far afield from their familiar precincts.

The theory that plants in general, especially forest trees, draw 

upon the ground-water supply has been expressed by numerous 

authorities for example, Ototzky,21 Storer,22 McGee,23 Bownman,2 * 

and Zon.25 Most of these writers have not been much concerned as 

to whether the trees and other plants actually withdraw water from 

the zone of saturation or whether they deplete the ground-water 

supply by absorbing the soil water before it can seep down to the 

water table, although they generally seem to imply actual removal 

from the saturated zone. As a rule, they have not been interested 

in distinguishing between different species in this respect. McGee 

conceived the idea that agricultural crops! throughout the Great 

Plains and other semiarid regions are supplied largely by ground 

water that rises from the zone of saturation by capillarity, but this 

suggestion is not well supported by the known facts.

The idea that plants of certain species more than others utilize 

water from the zone of saturation has been recognized, or at least 

suggested by several eminent botanists. Coulter,26 a leading authority on botany in this country, states that " there is what may be 

called a water level in soils, and it is important to note the depth of 

this level beneath the surface," and that "the depth of the water 

level helps to determine plant societies." Warming 27 states that 

" it would appear that the most potent and decisive factor [in the 

differences in vegetation in various parts of such a country as Denmark] is the amount of water in soil, and this in turn depends upon 

the depth to the water table and upon the physical characters of 

soil." He also calls attention to the zonal arrangement of the vege21 Ototzky, P., Les eaux souterraines, leur origine, leur regime et leur distribution, 

Deuxieme partie, Les eaux souterraines et les forets, principalement dans l«s plaines de 

latitudes moyennes, St. Petersburg, 1905 (published in Russian) ; Influence de forSts sur 

les eaux souterraines; Annales sci. agronomique, 2d ser., 3d year, vol. 2, pp. 476-477, 

1897; Influence des forests s.ur les eaux souterraines: Idem, 2d ser., 5th year, vol. 1, pp. 

300-316, 1899; Die Grundgewasser under den Waldern (abstract by Prof. K. Keilhack) : 

Geol. Centralbl., Band 2, Jahrgang 1902, pp. 630-631; Le niveau de 1'eau souterraine 

sous bois et hors en 1902, dans les landes de Gascogne; Annales sci. agronomique, 3d 

ser., vol. 1, No. 2, pp. 116-119, 1907.

23 Storer, P. H., Agriculture in some of its relations with Chemistry, pp. 47-114, New 

York, 1887.

83 McGee, W J, Field records relating to subsoil water: U. S. Dept. Agr. Bur. Soils 

Bull. 93, 1913.

24 Bowman, Isaiah, Forest physiography, pp. 41-54, New York, 1911.

86 Zon, Raphael, How the forests feed the clouds, in Caldwell, O. W., and Slosson, 

E. B., Science remaking the world, pp. 212-222, New York, 1924.

28 Coulter, J. M., Plants, a textbook of botany, p. 163, New York, 1900.

27 Warming, Eugen., Oecology of plants, pp. 45, 97, 131, 132, Oxford, 1909. The first 

edition of this treatise was published in Danish in 1895.

54386 27 2
12 PLANTS AS INDICATORS OF GROUND WATER

tation around every lake and pool and states that " differences of a 

few centimeters in the level of the water table suffice to evoke wide 

distinctions in the vegetation." He bases these statements largely 

on the work of other botanists, especially Fielberg, Raunkiar, and 

Massart.

In 1891 a botanical reconnaissance of the Mohave Desert and 

Death Valley regions, in California, was made by Coville.28 He 

described the zonal arrangement of the vegetation surrounding 

alkaline marshes or playas and divided the plants found in the 

desert into two significant classes those of humid habitat and 

those of arid habitat. The list of plants of humid habitat probably 

comes nearer to being a catalog of desert ground-water plants than 

anything else that has been published in this country. However, 

such abundant ground-water plants as greasewood and rabbit brush 

are included in the list of desert plants of arid habitat. Coville 

recognized three kind's of soil moisture hydrostatic, capillary, and 

hygroscopic and defined hydrostatic moisture as " free water, such 

as that which rises in a well or stands beneath a swamp" that is, 

ground water, as defined in this paper. He mentioned mesquite as 

an indicator of ground water where it occurs at depths of a few 

yards, and alkali sacaton (Sporobolus airoides) and other plants 

as indicators where it occurs at depths of only a. few feet. He dismissed the subject^ however, with the following statement: " Such 

sources of water are, however, not to be considered in a discussion 

of the desert proper. Capillary moisture also exists in the vicinity 

of springs and permanent underground water supplies; but in such 

cases, like the hydrostatic moisture from which it arises, it has no 

connection with the true desert vegetation."

The Desert Botanical Laboratory of the Carnegie Institution of 

Washington was established at Tucson, Ariz., in 1903, to study the 

relation of plants to an arid climate and to substrata of unusual 

composition. The botanists of this laboratory in their investigations 

have generally recognized the relation of certain species to the 

water table, and the subject has been studied by Spalding 89 and 

especially by Cannon.30 Eecent papers by Markle,31 Weaver,32 and

28 Coville, P. V., Botany of the Death Valley expedition: Contr. U. S. Nat. Herbarium, 

vol. 4, pp. 23, 31, 32, 35, 38, 39, 47, 1893.

29 Spalding V. M., Distribution and movements of desert plants: Carnegie Inst. Washington Pub. 113, pp. 5-17, 1909. 

80 Cannon, W. A., op. cit.

* Markle, M. S., Root systems of certain desert plants: Bot. Gazette, vol. 64, pp. 

177-205, 1917.

* Weaver, J. B., The ecological relations of roots: Carnegie Inst. Washington Pub. 

286; 1919; Root development of field crops: McGraw-Hill Book Co., N. Y., 1926.
INTRODUCTION ,,13

Clements,83 do not contain much that is applicable to the present 

subject.

One of the pioneers in the modern development of this subject is 

G. E. P. Smith, irrigation engineer in the University of Arizona, with 

whom is associated J. J. Thornber, botanist. As early as 1915 Smith 

made the statement that he had long held the hypothesis that the 

water absorbed and transpired by mesquite and other trees constitutes 

the principal loss from the ground-water reservoir.

A thorough and valuable investigation of the indicator significance 

of native plants in Tooele Valley, Utah,34 was made by the United 

States Department of Agriculture. In this investigation the relation 

of the principal ground-water plants, such as greasewood, to the 

water table was recognized, and much precise information was obtained bearing on the present subject. No specific study was made 

of this relation, however, as no data were obtained on the position 

of the water table, the chemical character of' the ground water, or 

the alkali or moisture content of the soil below the depth of 4 feet. 

Much valuable work has more recently been done by Shantz, Aldous, 

Piemeisel, and others 35 on the general subject of the indicator 

significance of native plants in the arid and semiarid regions of the 

United States, including some reference to ground water. Much of 

this recent work has been done in connection with the classification 

of the public domain by the Geological Survey with respect to its 

irrigability and its value for arid farming and grazing.

In most of the older water-supply papers of the United States 

Geological Survey dealing with discharge of ground water no mention is made of discharge by plants or indeed by evaporation from 

the soil, showing that these processes of ground-water discharge 

were not recognized or that their importance was not appreciated. 

In recent years, however, in the investigations by the Geological 

Survey of ground water in the desert regions, the great importance 

of these processes has been fully recognized and attention has necessarily been given to the plants that feed on ground water. The reports that have resulted from these investigations contain considerable

88 Clements, F. E., Plant indicators, the relation of plant communities to process and 

practice: Carnegie lust. Washington Pub. 290, 1920.

^Kearney, T. H., and others, Indicator significance of vegetation in Tooele Valley, 

Utah: Jour. Agr. Research, vol. 1, pp. 365-417, 1914.

85 Shantz, H. L., Grassland and desert shrub: Atlas Am. Agr., pt. 1, The physical 

basis of agriculture, sec. E, Natural vegetation, 1924. Aldous, A. E., and Shantz, H. L., 

Types of vegetation in the semiarid portion of the TJnited States and their economic 

significance: Jour. Agr. Research, vol. 28, pp. 99-127, 1924. Shantz, H. L., and 

Piemeisel, R. L., Indicator significance of the natural vegetation of the southwestern 

desert region: Jour. Agr. Research, vol. 28, pp. 721-801, 1924.
14 PLANTS AS INDICATORS OF GROUND WATER

specific information on the subject. 38 However, the work was done bygeologists, who were not equipped to study the botanical phases of 

the subject.

QUESTIONS THAT DESERVE FURTHER STUDY

Questions in regard to the ground-water plants that should receive more thorough study are as follows: What are the species that 

habitually depend on the zone of saturation? To what extent and 

under what circumstances do these species grow where they can not 

reach the zone of saturation? To what extent will other species 

utilize water from the zone of saturation, and to what extent are they" 

killed if the water table rises to their roots? Do the ground-water 

plants develop root systems in the capillary fringe, or do they 

send their roots into the zone of saturation? Do they avoid the 

alkali in the soil by sending their roots into or nearly to the zone

36 Reference is made especially to the following publications:

Ball, S. H., A geologic reconnaissance in southwestern Nevada and eastern California : 

U. S. Geol. Survey Bull. 308, p. 22, 1907.

Mendenhall, W. C., Some desert watering places in southeastern California and southwestern Nevada : U. S. Geol. Survey Water-Supply Paper 224, pp. 20, 21, 1909.

Meinzer, O. E., Ground water in Juab, Millard, and Iron Counties, Utah: U. S. Geol. 

Survey Water-Supply Paper 277, pp. 24, 25, 110, 128, 1911.

Lee, C. H., An intensive study of the water resources of a part of Owens Valley, Calif.: 

U. S. Geol. Survey Water-Supply Paper 294, p. 77, 1912.

Meinzer, O. E., and Kelton, F. C., Geology and water resources of Sulphur Spring: 

Valley, Ariz.: U. S. Geol. Survey Water-Supply Paper 320, pp. 171-187, 1913.

Meinzer, O. E., and Hare, R. F., Geology and water resources of Tularosa Basin, 

N. Mex.: U. S. Geol. Survey Water-Supply Paper 343, pp. 193-206, 306-311, 1915.

Carpenter, Everett, Ground water in southeastern Nevada: U. S. Geol. Survey WaterSupply Paper 365, pp. 13, 36, 4-3, 48, 59. 66, 69, 71, 73, 78, 1915.

Gregory, H. E., The Navajo country a geographic and hydrographic reconnaissance 

of parts of Arizona, New Mexico, and Utah: U. S. Geol. Surrey Water-Supply Paper 

380, pp. 130-131, 1916.

Schwennesen, A. T., Ground water in the Animas, Playas, Hacbita, and San laiis 

Basins, N. Mex.: U. S. Geol. Survey Water-Supply Paper 422, pp. 50-53, 144-149, 1918.

Meinzer, O. E., Geology and water resources of Big Smoky, Clayton, and Alkali 

Spring Valleys, Nev.: U. S. Geol. Survey Water-Supply Paper 423, pp. 92-104, 159-161, 

1917.

Waring, G. A., Ground water in Pahrump, Mesquite, and Ivanpah Valleys, Nev. and 

Calif.: U. S. Geol. Survey Water-Supply Paper 450, pp. 55, 56, 66, 1921.

Clark, W. O., and Riddell, C. W., Exploratory drilling for water and use of ground 

water for irrigation in Steptoe Valley, Nev.: U. S. Geol. Survey Water-Supply Paper 

467, pp. 15, 38, 39, 1920.

Brown, J. S., Routes to desert watering places in the Salton Sea region, California : 

U. S. Geol. Survey Water-Supply Paper 490-A, p. 13, 1920.

Thompson, D, G., Routes to desert watering places in the Mohave Desert region, California : U. S, Geol. Survey Water-Supply Paper 490-B, pp. 98, 99, 110, 1921.

Brown, J. S., The Salton Sea region, California a geographic, geologic, and hydrologic reconnaissance, with a guide to desert watering places: U. S. Geol. Survey WaterSupply Paper 497, pp. 16-19, 112-118, 1923.

Ross, C. P., The Lower Gila region, Arizona a geographic, geologic, and hydrologie 

reconnaissance, with a guide to desert watering places: U. S. Geol. Survey Water-Supply 

Paper 498, pp. 15, 16, 1923.

Bryan, Kirk, The Papago country, Arizona a geographic, geologic, and hydrologie 

reconnaissance, with a guide to desert watering places: U. S. Geol. Survey Water-Suppljr 

Paper 499, pp. 156, 157, 1925.

Thompson, D. G., The Mohave Desert region, California a geographic, geologic, and 

hydrologie reconnaissance, with a guide to desert watering places: U. S. Geol. Survey 

Water-Supply Paper 578 (in preparation).
PRINCIPAL SPECIES 15

of saturation, where they may obtain less concentrated water? To 

ivhat extent do the different species indicate the quality of the ground 

water? How do they adapt themselves to the fluctuations of the 

water table? What are the conditions where there is a gravelly

 subsoil, with a very thin capillary fringe, as compared with a loam

 subsoil that has a thick capillary fringe? What are the maximum 

.and minimum limits of depth to the water table for different species ? 

IVhat is the greatest depth from which ground water is lifted by 

plants? In species that habitually send their roots to considerable 

<lepths, what adaptations have the young plants for enduring 

drought until they can get their roots down to the capillary fringe ? 

Do plants of this kind propagate by runners so that the young plant

 can be nursed by the parent plant until it can get its roots down 

to the water? What changes take place in the physiology and 

growth of such plants when their roots reach ground water? Are 

the ground-water plants economical or wasteful of water, or are 

;some economical and others wasteful, or have they adaptations 

which permit them fo be economical or wasteful according to circumstances? How does the depth to the water table affect the rate 

at which a given species will lift water? What methods can be

 employed to determine for a given region the quantity of ground 

water that is annually discharged by the vegetation and that could 

\)G utilized by pumping from wells? What are the prospects of 

increasing the agricultural production of the arid and semiarid 

regions by developing ground-water plants of economic value?

ACKNOWLEDGMENTS

The writer is deeply indebted to A. E. Aldous, of the Geological 

Survey; to H. L. Shantz, of the Department of Agriculture; and 

to J. J. Thornber and G. E. P. Smith, of the University of Arizona, 

ior their critical examination of this paper and for the many valuable suggestions which they made; also to Kirk Bryan and D. G. 

Thompson, of the Geological Survey; A. E. Douglass, of the University of Arizona; and E. L. Piemeisel, of the Department of Agriculture, all of whom made valuable contributions to this investigation. Many of the photographs of plants in their natural habitat 

used in this paper were taken by D. G. Thompson or J. S. Brown 

in connection with their field work on desert watering places,

PRINCIPAL SPECIES OF PLANTS THAT HABITUALLY 

FEED ON GROUND WATER

ARRANGEMENT OF SPECIES

Before discussing the subject further it is desirable to describe the 

principal ground-water plants with reference to what is known of
16 PLANTS AS INDICATORS OP GROUND WATEE

their relation to the water table. As the subject has not been s^stematically studied no attempt will be made to give a complete list of 

species. However, for the purposes of hydrology it is hot so necessary to have a complete list of species as to recognize the comparatively few species that tend to form the dominant vegetation in their 

natural habitat. The descriptions of specific plants are practically 

limited to definite observations made by the writer or others of the 

relation of the species to the water table. This method unavoidably 

results in uneven treatment of the different kinds of plants and probably in the omission of some species that ought to be included.

No attempt is made to arrange the species that are described in 

strictly systematic order. In general the plants that indicate water 

very near the surface are described first and those that indicate successively greater depths to the water table are described later, except 

that the trees and woody bushes are described last even though they 

grow where the ground water is very near the surface.

No detailed descriptions are given of the species that are discussed, 

but more or less technical descriptions of most of them can be found 

in one or more of the following publications:

Coulter, J. M., Manual of the botany of the Rocky Mountain region from New 

Mexico to the British boundary, New York and Chicago, 1885.

Coulter, J. M., and Nelson, Owen, New manual of botany of the Rocky Mountains, New York, 1909.

Coville, F. V., Botany of the Death Valley expedition: Contr. U. S. Nat, 

Herbarium, vol. 4, pp. 55-233, 1893.

Parish, S. B., Plant ecology and floristics of Salton Sink: Carnegie Inst. 

Washingon, Pub. 193, pp. 104-114, 1914.

Shantz, H. L., and Zon, Raphael, Natural vegetation: U. S. Dept. Agr. 

Atlas Am. Agr., pt. 1, sec. E, 1924.

Sudworth, G. B., Forest trees of the Pacific slope, U. S. Forest Service, 1908. -

Tidestrom, Ivar, Flora of Utah and Nevada: Contr. U.. S. Nat. Herbarium, 

vol. 25, 1925.

Wooton, E. O., and Standley, P. C., Flora of New Mexico: Contr. U. S. Nat. 

Herbarium, vol. 19, 1915.

Wooton, E. O., and Standley, P. C., The grasses and grasslike plants of New 

Mexico: New Mexico Coll. Agr. and Mechanic Arts Bull. 81, 1912.

RUSHES, SEDGES, AND CAT-TAILS

Several species of rushes (Juncus), sedges (Scirpus), and cattails (Typha) commonly grow along the margins of shallow bodies 

of surface water and are frequently found in the pools and currents 

of water produced by springs. To some extent they also grow where 

the water table stands a short distance below the surface, and in 

these situations they may properly be regarded as ground-water 

plants. They generally though not invariably indicate water of 

good quality.37

87 Mendenhall, W. C., op. cit. (Water-Supply Paper 224), p. 20.
PRINCIPAL SPECIES 17

In Tooele Valley, Utah, Juncus baltieus was found in association 

with salt grass where the water table is near the surface.33 A number of species of rushes, sedges, and cat-tails are given in Coville's 

list of desert plants of humid habit, and detailed information as to 

their occurrence in the desert regions are given both in Coville's 

catalog of species 39 and in the catalog of plants in the Salton Sink 

by Parish.40

As the plants of this type grow largely where the water is visible 

at the surface or where there are other evident signs of water their 

value as indicators is accordingly limited, but even in these places 

they may serve a useful purpose in attracting attention to the 

localities where the water occurs. They are, moreover, valuable in 

indicating areas where a perennial supply of ground water is present 

in distinction from wet areas produced by temporary supplies of 

surface or ground water, where such plants can not as a rule survive 

the dry periods.

HEEDS AND CANE

The common reed, or giant reed grass (Phragmites communis) 

is found along streams and ponds and also in many places where there 

is no surface water but where the ground water is not far below 

the surface. It occurs in the main area of shallow ground water in 

the lower basin of Big Smoky Valley, Nov., and in the Bye Patch, 

near Tonopah (p. 18), but it was not seen except where the ground 

water is near the surface. It was observed in the Mohave Desert 

region,41 where the water table was only 3 or 4 feet below the surface.

Wild cane is listed by both Ball 42 and Brown 43 as a reliable 

indicator of shallow ground water. It was observed by Brown in 

Coachella Valley, Canebrake Canyon, and a few other places in the 

Salton Sea region, California. It may grow to a height of 10 feet or 

more as a tall jointed stalk with green leaves at the top, thus attracting attention to localities where water can be found.

WILD RYE

The species of wild rye commonly called giant rye grass or giant 

wild rye (Elymus c&ndensatus) , which in some places grows 10 feet 

high, is widely distributed through the West. It was observed in 

areas of shallow ground water in Nevada, particularly in the socalled Rye Patch, in Ralston Valley, east of Tonopah. Ball,44 who 

made a geologic reconnaissance in southwestern Nevada and adjacent parts of California, in 1905, in describing signs of water in

a'Kearaey, T. H., etc., op. cit, p. 407.

88 Coville, P. V., op. cit.

« Parish, S. P., op. cit.

41 Thompson, D. G., op. cit.

<*Ball, S. H., op. cit. (Bull. 308), p. 22.

** Brown, J. S., op. cit. (Water-Supply Paper 497), p. 113.

**Ball, S. H., op. cit. (Bull. 308), pp. 22, 24.
18 PLANTS AS INDICATORS OF GROUND WATER

the desert, states that " where rye grass and cane grow there is water 

at the surface or at a moderate depth." Hillman,45 in a discussion 

of the forage value of this species states: " The plants do not 

occur on the dryest hills but on rather lower land. The grass is 

frequently met in the subalkaline parts of the valleys and at the 

entrances to the mountain canyons." In Steptoe Valley, Nev., giant 

wild rye was found by Clark and Kiddell 46 in tracts where the 

depth to the water table does not exceed 12 feet. In Tooele Valley, 

Utah, the same species was found in the greasewood-shadscale 

association where the water table is at only moderate depth but not 

extremely near the surface.47 In areas of somewhat more abundant 

precipitation giant wild rye apparently grows where the water 

table is not within reach. Thus a good growth of this species is 

reported by Aldous in association with sagebrush in upland tracts 

of San Pete Valley, Utah, where the average annual precipitation is about 15 inches. The wheatlike rye grass (Elymus triticoides] is reported by Thornber as a ground-water plant, growing 

invariably in rich valley soils where the ground water is relatively 

near the surface.

Both the giant reed grass and the giant rye grass are abundant 

in the Eye Patch, in Kalston Valley, Nev., in association with salt 

grass, big greasewood, and rabbit brush. At the Rye Patch were 

sunk the wells that furnished the first adequate water supply for 

the city of Tonopah, 'the water being pumped through a pipe line 

11 miles long and lifted a height of 600 feet. The Rye Patch is 

situated along the axis of a desert valley about 50 miles long, at a 

point where an underground barrier is believed to be formed by 

lava beds. So far as known, it is the only area of shallow ground 

water along the axis of this large valley and affords a conspicuous 

example of a very valuable water supply that was located by the 

presence of ground-water plants. In the first wells that were sunk 

the water level was originally 8 feet below the surface but is now 

somewhat lower. In some places in the Rye Patch ground water 

stands within 5 feet of the surface. The precise depth to the water 

table at the points where the reed grass and wild rye are growing 

was not determined.48

Certain plants of the character of wild rye are also found in 

areas of shallow ground water in the humid eastern part of the 

country, as, for example, near Washington, D. C., where they indicate localities^ in which fairly permanent water supplies can be obtained by digging shallow wells.

45 Hillman, F. H., Field notes on some Nevada grasses: Nevada Agr. Exper. Sta., 

Bull. 33, p. 11, 1896.

46 Clark, W. O., and Riddell, C. W., op. cit. (Water-Supply Paper 467), p. 39.

47 Kearney, T. H., and others, op. cit., pp. 400-401.

*3 Meinzer, O. E., op. cit. (Water-Supply Paper 423), pp. 95, 124-126.
PRINCIPAL SPECIES 19

SALT GRASS

One of the most widespread and trustworthy of all plants as an 

indicator of ground water is the common salt grass (Distichlis 

spicata). It is described by Wooton and Standley 49 as "a coarse 

perennial with stiff leaves and stems, a rather strict panicle, sometimes a little branched, with flattened spikelets of about 10 or a 

dozen flowers. It is a sod-forming grass, spreading by underground 

stems." (See fig. 2.) Doubtless if full information were available 

it would be found that salt grass is growing in many places that 

are watered from other sources than ground water or in clayey soils 

with considerable moisture but without a definite water table. The 

fact will always remain, however, that throughout a vast desert 

region in the western part of the United States this species is normally a ground-water plant, that it faithfully shows the presence 

and approximate extent of literally hundreds of areas of shallow 

ground water, and that it can be used with great confidence as an 

indicator of ground water by anyone who has a reasonable amount 

of experience and judgment. (See pi. 3, A.)

Salt grass has been described as a ground-water plant in California,50 Arizona,51 New Mexico,52 Utah,53 Nevada,54 Nebraska,55 and 

Wyoming,55 but it also occurs in other Western States.56

In an intensive study by Lee 57 of the discharge of ground water 

in the Independence district of Owens Valley, Calif., it was found 

that the belt of grass and alkali land in this district from which 

ground water is discharged covers about 55 square miles, or 35,000 

acres. (See fig. 3.) Most of this belt is covered with salt grass, 

which grows where the depth to ground water does not exceed about 

8 feet. In about 12 square miles of this belt the average depth to 

the water table is less than 3 feet, in about 18 square miles it is be43 Wooton, B. O., and Standley, P. C., The grasses and grasslike plants of New 

Mexico: New Mexico Agr. Exper. Sta. Bull. 81, pp. 120, 121, 1912.

60 Mendenhall, W. C., op. cit. (Water-Supply Paper 224), p. 21. Lee, C. H., op. cit. 

(Water-Supply Paper 294), pp. 14, 77, 84, 85. Thompson, D. G., op. cit. (Water-Supply 

Paper 490-B), p. 98. Brown, J. S., op. cit. (Water-Supply Paper 497), p. 113. Shantz, 

. H. L., and Piemeisel, R. L., op. cit., p. 762.

61 Gregory, H. E., op. cit. (Water-Supply Paper 380), p. 131. Shantz, H. L., and 

Piemeisel, R. L., op. cit., p. 798.

62 Meinzer, O. E., and Hare, R. F., op. cit. (Water-Supply Paper 343), pp. 193, 198. 

Wooten, E. O., and Standley, P. C., op. cit. pp. 120, 121.

^Kearney, T. H., and others, op. cit., pp. 407, 408.

"Ball, S. H., op. cit., p. 24. Meinzer, O. E., op. cit. (Water-Supply Paper 423), pp. 

95, 100. Waring, G. A., Ground water in Reese River basin and adjacent parts of 

Humboldt River basin, Nev.: U. S. Geol. Survey Water-Supply Paper 425, p. 110, 1919; 

Ground water in Pahrump, Mesquite, and Ivanpah Valleys, Nev. and Calif.: U. S. Geol. 

Survey Water-Supply Paper 450, p. 66, 1921. Clark, W. O., and Riddell, C. W., op. cit. 

(Water-Supply Paper. 467), p. 39.

63 Meinzer, O. E., Ground water for irrigation in Lodgepole Valley, Wyo. and Nebr.: 

U. S. Geol. Survey Water-Supply Paper 425, p. 48, 1919.

^Aldous, A. E., and Shantz, H. L., op. cit., p. 111. Shantz, H. L., op. cit., p. 26. 

S7 Lee, C. H., op. cit. (Water-Supply Paper 294), pp. 14, 80, 84, 85, 131; pi. 25.
20 PLANTS AS INDICATORS OP GROUND WATER

tween 3 and 4 feet, and in about 25 square miles it is between 4 and T 

feet. The annual fluctuation of the water table in this belt as observed 

in 122 wells ranged from about 1.5 to 4 feet and averaged 3.14 feet.

/;

PIGUEB 2. Salt grass (Distiohlis spioata). After Wooton and Standley

The discharge of ground water by transpiration from salt grass 

and other vegetation and by evaporation from the soil was found 

to average about 2 feet a year over the area and to vary inversely 

about as the depth to the water table, down to depths of 8 feet (p. 86).
PRINCIPAL SPECIES 21

In Figure 3 lines indicating equal depth to ground water are drawn to 

showtlepths of 8, 4, and 3 feet. In the vicinity of the 8-foot line salt

R. 34 E.

FIGUBB 3. Map of Independence district of Owens Valley, Calif., showing area of 

ground-water discharge. (After Lee, C. EL, op. cit. (Water-Supply Paper 

294), pi. 25) .

grass begins to appear and gradually becomes dominant with increasing depth to the water table. Farther east, near and within the area
22 PLANTS AS INDICATORS OF GROUND WATEE

inclosed by the 4-foot line, it grows luxuriantly. Within the 3-foot 

line fresh-water grasses thrive where there is sufficient surface water 

to leach out and carry away most of the alkali, but the salt grass 

grows well even where the soil contains considerable alkali.

In 15 localities in Big Smoky Valley, Nev., in which salt grass was 

growing, the depth to the water table was found to range from 2 to 

11.7 feet in the fall, when the water table was about at its lowest 

level for the year.58 In Clay ton Valley, Nev., in the same season 

salt grass was dominant in a zone bordering the playa in which the 

depth to the water table did not greatly exceed 10 feet, but it-was 

evident that the salt grass extended slightly beyond the 10-foot 

limit.59

In many places salt grass covers the ground virtually to the exclusion of other vegetation. However, out of 18 localities in Big Smoky 

Valley there were only 2 in which salt grass was growing alone; in 9 

localities it was associated with rabbit brush, in 7 with greasewood,. 

and in 1 or 2 each with pickleweed, alkali sacaton, salt bush (Atriple® 

torr&yi), willow, poplar, and sagebrush. In Ralston Valley it is associated with greasewood, rabbit brush, wild rye, and giant reed grass. 

In Clayton Valley it is associated with pickleweed, rabbit brush, and 

seepweed.

In Tooele Valley, Utah, salt grass is a leading species on the grass 

flat, which lies between the greasewood-shadscale belt and the salt 

flats bordering Great Salt Lake. The grass flat covers a gently 

sloping or nearly level expanse and appears to be lower in altitude 

than some of the ridges and hillocks situated between it and the 

shore of the lake. The area is thus somewhat analogous to a coastal 

lagoon and may have had a similar origin. During the greater part 

of the year it has a very moist soil, obviously because the w'ater table 

is close to the surface. Salt grass is more or less abundant in all 

parts of the grass flats and also penetrates the salt flats, where in 

some places it is associated scatteringly with pickleweed and in other 

places it forms dense mats. In the wetter portions of the grass flat 

salt grass is the principal component of a meadowlike vegetation, 

with Juncus balticus, Suaeda erecta, Puccinellia airoides, and Glau® 

maritima as chief associates and with numerous other species scatteringly present. 60

Mexican salt grass (Eragrostis obtusiflora) has been observed at 

the margins of the playas in southwestern New Mexico 61 and southeastern Arizona.62 In regard to this species Wooton and Standley

6S Meinzer, O. B., op. cit. (Water-Supply Paper 423), p. 100, pi. 12 

59 Idem, pp. 144, 145.

'K'Kearney, T. H., and others, op. cit., pp. 405, 407, 408, 413. 

61 Wooton, B. O., and Standley, P. C., op. cit., p. 120.

^Meinzer, O. E., and Kelton, F. C., op. cit. (Water-Supply Paper 320), pp, 172-181, 

184, 186.
PRINCIPAL SPECIES 23

state that " it might easily be mistaken for ordinary salt grass, which 

it resembles in many respects, but the inflorescence is somewhat different. It is of some importance in the region mentioned and may occur 

elsewhere, having been overlooked on account of its similarity to 

ordinary salt grass." Mexican salt grass was observed at 13 localities in Sulphur Spring Valley, Ariz., at which the depth to the water 

table was known. In these localities the depth to the water table 

ranged from 4 to 15 feet in the fall of a dry year, when the water 

table was doubtless at a low stage. Out of 27 localities there were 

2 in which this grass was growing alone, whereas in 21 it was associated with alkali sacaton, in 4 with seepweed, in 3 with mesquite, in

2 with chamiso, and in at least 4 wi

SAGA

Sporobolus airoides, a species of 

common names, including tussock g 

ton, fine-top sacaton, purple top, 

coarse grass, 2 to 3 feet high, 

clothed below by dead sheaths. ( 

feathery purple panicles of this gr 

the vegetation. It is reported to o 

and southward into New Mexico and

Studies of this grass in relation 

ley, Utah, and Sulphur Spring 

commonly a ground-water plant 

tangible information is at hand as 

parts company with the water tab 

that were especially mentioned by 

water in Death Valley. He states t 

special importance to the desert tra 

within a few feet of the surface, of

In Tooele Valley it grows in assc 

forming the so-called Sporobolus-G 

covers a large part of the grass fl 

occur where the other is absent, bi 

ciated. Salt grass is also usually 

munity. The Spor&bolus-Ohrysotl 

outside by the greasewood-shadsca 

salt-grass zone. In the few tests oj 

the Sporobolm-Chrysoth&mnws zon 

over that represented by the wiltin 

from the first or second foot down

ti grama grass.

ON

sacaton that is known by several 

rass, alkali sacaton, red-top sacaunch grass, and salt grass, is a 

ith stems forming large tufts, 

 >ee fig. 4.) In late summer the 

ss are a characteristic feature of 

ur from California to Nebraska 

a Texas.63

o its environment in Tooele Valalley, Ariz., indicate that it is 

n these valleys, but not much 

to whether in sdme localities it 

e. It is one of the two species

Doville 64 as indicators of ground 

hat this grass " has come to be of 

eler, for it indicates the presence, 

water sufficiently fresh to drink."

iation chiefly with rabbit brush, 

hri/s&thamnus community, which 

it. Either of these species may

; as a rule they are closely assoor less abundant in this comamnus zone is bordered on the

! zone and on the inside by the

soil moisture that were made in 

considerable excess of moisture

; coefficient was generally found

suggesting the extension of the

more

63 Coulter, J. M., op. cit, p. 411. 

84 Coville, F. V., op. cit., p. 35.

T. H., and others, op. cit., pp. 40ft. 407.
24 PLANTS AS INDICATORS OF GROUND WATER

capillary fringe virtually to the surface and the water table at a 

depth of only a few feet. The association of alkali sacaton with salt 

grass and rabbit brush indicates a depth to the water table not

FIGUEB 4. Alkali sacaton or tussock grass (Sporobolus airoides). 

(After Wooton and Standley, op. cit., p. 77)

exceeding 10 or 15 feet. The alkali content of a' number of soil 

samples taken where this grass was growing was found to be very 

moderate, averaging only about one-third of 1 per cent.
PRINCIPAL SPECIES 25

In Sulphur Spring Valley the zone of ground-water vegetation 

surrounding, the barren playa is divided more or less definitely into 

belts, seepweed being dominant next to the playa, then Mexican salt 

grass associated with seepweed, then alkali sacaton with the salt 

bush chamiso, and finally mesquite. The alkali sacaton is prominent, occurring throughout a wide belt. It was found in 24 localities where the depth to the water table and the alkali content of the 

soil were determined. In these localities the depth to the water 

table at a low stage ranged from 4 to 27 feet, but in 19 of them it 

was not more than 15 feet, and in 11 it was not more than 10 feet. 

Alkali sacaton was also found in a, few localities where the depth 

to the water table was not known but was estimated to be greater 

than 27 feet. In St of the 24 localities it was found in association 

with mesquite along the outer edge of the sacaton belt, in 11 it was 

found in association with Mexican salt grass in the inner part of 

the sacaton belt or within the salt-grass belt, and in 2 it was found 

in association with seepweed. The soil at the sacaton localities that 

were investigated generally contains only moderate amounts of alkali. 

The belt in which this species is dominant has rather definite limits 

and is closely related to the water table. Its luxuriance in this belt 

shows clearly that it habitually feeds on water from the zone of 

saturation; apparently, however, it has spread in some localities to 

high land where its roots do not reach down to the capillary fringe. 

In southwestern New Mexico some alkali sacaton was reported by 

Schwennesen where the water table was estimated to be as much as 

100 feet below the surface.65

Another species of sacaton (Sporobolus wrightii), also known as 

coarse-top sacaton to distinguish it from Jane-top sacaton, or alkali 

sacaton, occurs widely throughout the arid regions in,localities where 

considerable water is available. There is evidence that it grows in 

places where the soil is periodically well moistened by flood waters, 

but also in places where it feeds on ground water. The record furnished by a water-stage recorder maintained by G. E. P. Smith 

ever a well in a sacaton tract shows that in this locality the coarsetop sacaton is a ground-water plant. J. J. Thornber 66 states that in 

Arizona the species typically depends on ground water.

PICKLEWEED, SAMPHIRE, SEEPWEED, AND OTHER SUCCULENT 

ALKALI-RESISTANT PLANTS

The succulent alkali-resistant bush here called pickleweed (Allenrolfea ocddentalis) fringes the barren playas in many desert basins 

and is an indicator of shallow ground water. (See figs. 5 and 9.) 

In Big Smoky Valley, Nev., it occurs in association with salt grass

65 Schwennesen, A. T., op. cit. (Water-Supply Paper 422), p. 144. 

M Personal communication.
26 PLANTS AS INDICATORS OF GROUND WATER

and 'also adjacent to the barren play as on alkaline soil beyond 

the limits of the salt grass. In one locality where this species is 

growing the depth to the water table was found to be only 2 feet.6T

In the Tularosa Basin, N. Mex., Allenrolfea occidentals is associated with salt grass in the area of alkaline soil and shallow ground 

water 68 and occurs also on soil that is too alkaline, too dense, or too

FIGCKE 5. Pickleweed (Allenrolfea ocddentalis). (From Kearney, T. H., and others, 

op. cit., fig. 11.) A, Detail of a fruiting branch showing the cylindrical, fleshy, 

practically leafless stems; B, a plant showing the large tap root and rather scanty 

lateral roots characteristic of .this species.

frequently submerged for salt grass. In this basin it was observed 

in four localities in which the depth to the water table in the fall 

ranged from 1.3 to 6 feet; also in a locality in which the depth was 

11 feet and in another in which it was 20 feet.69 In these last two 

localities the soil was shown by analysis to contain large amounts of 

alkali. It would be instructive to ascertain whether in these localiOT Meinzer, O. B., op. cit. (Water-Supply Paper 423), pp. 95, 100.

osMeiiizer. O. E., and Hare, R. F., op. cit (Water-Supp y Paper 343), pp. 193-199.

08 Idem, pp. 306-311.
PBINCIPAL SPECIES 27

ties the plant sends its roots down to the capillary fringe or whether 

it has spread beyond its limits as a ground-water plant upon the 

highly alkaline soil. The long taproot of this species-suggests that 

it may be able to obtain ground water from considerable depths, 

although it is most abundant where the water table is very near the 

surface.

Allenrolfea occidentalis is described by Parish 70 as occurring, in 

association with Dondia torreyana, on the most alkaline soil of the 

large flat extending northward from the Salton Sea, where the soil 

is commonly moist from rising ground water.

In the report on Tooele Valley, Utah,71 is given the following detailed and exceedingly instructive description of the salt flat that 

borders Great Salt Lake and of the occurrence of All&rvrolfea ocddentalis and associated species on this flat:

Along the margin of Great Salt Lake there is a belt of low land which 

varies in width from about 4 miles, near the axis of the valley, to a mere fringe 

on the east and west sides where the mountain ranges approach, the lake1 

shore. Much ^of this area is covered with water at times but in. summer 

presents a dazzling white surface due to the heavy crust of salts. These flats 

are divided into shallow basins of greater or less extent, separated by low 

ridges and hummocks. All but the lowest of these elevations are occupied by 

the greasewood-shadscale association, while the basins and flats when not 

altogether devoid of vegetation support a few extremely halophytic species 

which occur either as scattered individuals or in crowded colonies.

The two environments are ecologically quite distinct. * * * Greasewood 

occurs not only on the higher ridges in association with shadscale but also on 

the lower hummocks and at the edges of the depressions in association with 

Allenrolfea. Shadscale, on the other hand, is not found in the depressions, 

nor do the typical salt-flat species occur on the higher ridges.

The vegetation of the flats and depressions comprises several communities, 

each characterized by the presence of a single species Allenrolfea oocidentalis, 

Salicornia utahensis, and SaUcomia rubra. The first of these is by far the 

most abundant and widely distributed. These three species appear to be the 

most salt-resistant of the flowering plants of this region, taking possession of 

the land left bare by the recession of the lake as soon as its salt content has 

been reduced sufficiently from the point of saturation with the excessively saline 

lake water to permit the growth of any flowering plant.

In the Allenrolfea community the dominant species, Allenrolfea occtdentalis, 

is a shrubby plant with numerous cylindrical, jointed, fleshy, practically leafless 

branches and a large taproot. In Tooele Valley it rarely exceeds a height of 

2 feet There is considerable variation in the habitat of this plant, but it 

develops most characteristically on low hummocks on the salt flats and near 

the bases of the higher ridges, usually preferring a slightly better drained and 

less saline soil than the species of Salicornia. In places, however, it is seen 

scattered over the surface of the fiats, the dark brownish-green tufts of 

Allewolfea contrasting strikingly with the pure white of the saline incrustation. The thinness of the stand is shown by a plat of a typical 10-meter

»Parish, S. B., op. cit., pp. 92, 93.

n Kearney, T. H., and others, op. cit., pp. 408-412.

54386 27 3
28 PLANTS AS INDICATOES OP GKOTJND WATEK

quadrat in which were growing only 110 individual plants of Allenrolfea ocddentalis, the only species present. Often, as shown in this plat, Allenrolfea, 

forms a pure community. On higher and better-drained ground, however, it is. 

frequently associated with greasewood (Sarcobatus v&rmiculatus) and with 

Suaeda [Dondia,] moqumii, while in the wetter depressions it often mingles 

with Salicornia utahemis. Plants of greasewood, when growing with Allenrolfea, are usually stunted and sickly looking. * * *

It is clear from the tests made of the moisture equivalent, wilting coefficient, 

and salt content of the soil that the presence of this plant is an almost invariable indicator that the soil (1) contains moisture available for growth, at 

least below the surface foot, throughout the summer; and (2) is excessively 

saline to a depth of at least 4 feet.

Salicomia, utaJiensis is a nearly leafless plant with fleshy, jointed stems. 

It resembles small plants of Allenrolfea but is readily distinguished by the 

light blue-green color and by the fact that the branches are opposite, while in 

Allenrolfea they are alternate. It spreads by creeping rootstocks and forms 

pure colonies of greater or less size, which sometimes cover the bottoms of 

depressions, sometimes occupy hummocks elevated but a few inches above the 

general surface of the flats. In this case the appearance is much like the 

Allenrolfea hummocks, except that the latter are higher and the plants are 

larger and darker colored. This Salicornia is also found in association with 

Allenrolfea and with Distichlis.

No determinations were made of the moisture equivalent and moisture 

content of the soil where this community occurs, but two borings carried to 

a depth of 30 inches and 12 inches, respectively, showed that abundant moisture 

was present throughout that depth, as would be expected from the slight elfevation of the land above the water surface of the lake.

Salicornia rubra, a small, shallow-rooted annual species of Salicornia, is 

found most abundantly in pure communities along drainage channels in the 

salt flats. The patches of Salicomia rubra are very conspicuous late in the 

summer, owing to the bright-red color then assumed by the plants. Scattered 

individuals of this species were also observed far out on the otherwise bare 

salt flats. - I

The species of seepweed that is also called iodine weed and inkweed (Dondia torreyana, also identified as Dondia moquimi and 

Suaeda torreyana or moquinii?) is a perennial shrub, commonly 

having a purplish color and found in Nevada, California, and other 

States, on alkaline soil where more than an ordinary supply of 

moisture is available. It frequently occurs adjacent to the greasewood zone on land that is somewhat more alkaline and lies a little 

closer to the water table. In Clayton Valley, Nev., it occurs, in 

association with salt grass, rabbit brush, and pickleweed, near the 

playa, in a zone in which the depth to the water table does not 

greatly exceed 10 feet. In Ralston Valley it occurs with greasewood 

along the margin of the shallow-water tract. In Big Smoky Valley,, 

however, it appears not to be a reliable indicator of ground water, 

for it grows in places that are far above the water table, such as the 

undrained areas on the landward side of ancient beach ridges where 

storm waters accumulate.
PRINCIPAL SPECIES 29

-In Sulphur Spring Valley, Ariz., is found an alkali-resistant bush 

commonly called burroweed and identified as a species of Suaeda 

(Doncfiia). It grows in the belt of shallow ground water and alkaline soil immediately surrounding the barren playa, in association 

with Mexican salt grass, and also in clumps at the margin of the 

playa where the surface is otherwise destitute of vegetation. In 

three localities of Dondia investigated in Sulphur Spring Valley 

the depth to the water table at a low stage ranged from 4 to 7 feet. 

In one locality, where the depth to the water table was not determined but was estimated to be 15 feet, this species was found, though 

not as the dominant vegetation.72

Two other species of alkali-resistant plants that indicate ground 

water were mentioned by Mendenhall 73 as growing in California 

lowland purslane (Sesumum portulacastrum) and wild heliotrope 

(Heliotropicwn curccsswtiicum) , locally called " Chinese pusley." The 

lowland purslane grows in moist soils and indicates ground water 

but usually water of poor quality. The wild heliotrope is described 

by Coulter 74 as occurring along the seacoasts and also on saline soils 

in the interior. Mendenhall states that it grows only in moist soils, 

but as it has strong alkali-resistant powers the ground water on which 

it feeds may be brackish.

YEBBA MANSA

Yerba mansa, a perennial herb which somewhat resembles the plantain weed in appearance has been listed as a ground-water plant in 

southern California by both Lee 75 and Thompson.76 Lee states that 

it formerly grew in association with salt grass in the valleys of the 

western slope of San Diego County, Calif., where the water table 

commonly stood within 5 feet of the surface. Thompson observed 

it in the vicinity of Newberry Spring, in the Mohave Desert region, 

where the water table is only 3 or 4 feet below the surface.

BABBIT BBTJSH AND BELATED SPECIES

One of the most conspicuous of the ground-water indicators in 

Nevada, Utah, and adjacent regions is the well-known desert bush 

commonly called rabbit brush or broom sage. The principal groundwater species of rabbit brush (Chrysothamnus graveolens) is a shrub 

with slender, whiplike branches that have small, narrow leaves.

73 Meinzer, O. E., and Kelton, P. C., op. cit. (Water-Supply Paper 320), pp. 172-181, 

184,186. 

 Mendenhall, W. C., op. cit. (Water-Supply Paper 224), p. 20.

74 Coulter, J. M., Manual of the botany of the Rocky Mountain region, from New Mexico 

to the British boundary, p. 258, 1885.

75 Ellis, A. J., and Lee, C. H., Geology and ground waters of the western part of San 

Diego County, Calif.: U. S. Geol. Survey Water-Supply Paper 446, p. 110, 1919. 

78 Thompson, D. G., op. cit. (Water-Supply Paper 578).
30 PLANTS AS INDICATORS OP GROUND WATER

In late summer it is made conspicuous by numerous small heads of 

yellow flowers which resemble those of golden rod.77 In the 

Mohave Desert region, Calif., Chrysothaxm/nus mohaven&is was 

observed by Thompson 78 as a ground-water plant. Babbit brush 

has been described as a ground-water plant in Big Smoky,79 Ralston,80 

Clayton,81 and Steptoe 82 Valleys, Nev.; in Tooele Valley 83 and Sevier 

Desert,84 Utah; and in Owens Valley 85 and the Mohave Desert 

region,86 Calif.

It is one of the most common plants in the shallow-water areas 

of Big Smoky Valley. It prefers the parts of these areas that have 

some drainage but also grows in very alkaline soil and is a fairly 

reliable indicator of shallow ground water. The zone of dominant 

rabbit brush is in a general way bordered on the inside by the saltgrass zone and on the outside by the greasewood zone. In seven 

localities of rabbit brush that were investigated the depth to the 

water table at a low stage ranged from 2.5 to 12 feet, and in another 

locality the depth was estimated to be 14 feet. In all eight of these 

localities the rabbit brush was associated with salt grass, and in all 

except one it was also associated with greasewood. In two of the 

localities it was associated with sagebrush (Artetnisia trid&ntatia) , 

which does not depend on ground water. The alkali in the soil of 

a few of the localities that were tested ranged from 0.20 to 3.15 

per cent and averaged a little over 1 per cent.

In the Sevier Desert and some other tracts of shallow ground 

water in western Utah rabbit brush grows in close relation to greasewood but generally on somewhat better-drained and less alkaline 

soil. On some of the low ridges formed by abandoned river channels 

the greasewood is largely displaced by rabbit brush, and some abandoned channels can be traced long distances by such bands of yellowtopped brush winding through the monotonous expanse of grease- 

'wood. In Tooele Valley, where rabbit brush grows in association 

with alkali sacaton and salt grass, the alkali content of the soils 

that were tested is only very moderate. A considerable excess of 

moisture over that needed to prevent wilting suggests the presence 

of the capillary fringe and the existence of the water table probably 

within 10 feet of the surface. In studies made in Steptoe Valley,

77 Kearney, T. H., and others, op. clt., p. 406.

78 Thompson, D. G., op. cit.

ra Melnzer, O. B., op. clt. (Water-Supply Paper 423), pp. 95, 98, 100, 159-161.

80 Idem, p. 125.

81 Idem, p. 145.

82 Clark, W. 0., and Riddell, C. W., op. cit., p. 39.

88 Kearney, T. H., and others, op. clt., pp. 406, 407.

"Meinzer, 0. E., op. cit (Water-Supply Paper 2T7), pp. 24, 110.

86 Lee, C. H., op. clt. (Water-Supply Paper 294), p. 77; The determination of safe yield 

of underground reservoirs of the closed-basin type: Am. Soc. Civil Eng. Trans., vol. 78, 

pp. 238, 250, 1915.

88 Thompson, D. G., op. cit.
PRINCIPAL SPECIES 31

Nev., the conclusion was reached that in general rabbit brush occupies tracts where the depth to the water table is between 8 and 15 

feet.

Small individuals of rabbit brush or of a plant resembling rabbit 

brush are widely distributed over the alluvial slopes far above the 

water table. In Tooele Valley the species Ghrysothamrms maricmus 

occurs in the shadscale association far above the water table and 

almost certainly without any relation to it. Further investigation 

is needed to determine to what extent the species Ghn/sothainwus 

ffraveolens parts company with the water table. Quite without such 

an investigation, however, there is generally little difficulty in determining the localities where the luxuriant and abundant individuals 

of rabbit brush are true indicators of shallow ground water.

The rayless goldenrod (Bigelovn Jvartwegii) appears to behave 

much like the rabbit brush, and the writer may have confused these 

two species in his observations. Apparently both have a tendency 

to occupy ground on which the native vegetation has been destroyed 

by grazing or cultivation, and both will grow in dry situations as 

small plants but will make a notably ranker growth where ground 

water is within reach.

ARROW WEED, BATAMOTE, AND JACATE

Arrow weed (Pluohea sericea) is a tall, straight-stemmed shrub 

that seldom branches and grows in rather dense thickets. Its wood 

was used by the Indians to make arrows.87 It is reported to be a 

ground-water indicator in the Mohave Desert region, California, by 

Thompson,88 and in the Salton Sea region, California, by Brown,89 

who states that although it is a reliable indicator of ground water 

it is likely to grow where the depth to the water table is several feet 

and possibly as much as 25 feet. Usually, however, a heavy growth 

signifies water within 5 or 10 feet of the surface. Thompson noted it 

growing abundantly along the flood plain of Colorado River near 

Needles, where the depth to water was only a few feet. Brown states 

that arrow weed is common along dry arroyos where there is a shallow 

subsurface flow and in basins where ground water is near the surface. 

It also grows freely beside pools and running streams.

The batamote bush (Baccharis glutinosa) is regarded by G. E. P. 

Smith as an indicator of ground water. In a letter he makes the 

following remarks in regard to it:

There are several other plants which I think you should list. One of them 

is the batamote, of which there are three varieties. While it will grow in my

^Aldous, A. E., and Shantz, H. L., op. cit., p. 113.

88 Thompson, D. G., op. dt. (Water-Supply Paper 490-B), p. 98; also Water-Supply 

Paper 578. 

88 Brown, J. S., op. cit., p. 113.
32 PLANTS AS INDICATORS OF GROUND WATER

dooryard, if planted where it can steal water, yet it does not seem to belong 

there, but when growing along the bottom lands with its feet in the water it 

becomes a very large shrub or bush almost a tree. It is often associated 

with arrow weed.

The shrub called jacate (Hymenoclea monogyna) commonly forms 

thickets in the valley lands of Arizona and in places attains a 

height of 8 to 10 feet. It generally indicates the occurrence of 

ground water near the surface.

SALTBUSHES

The different species of saltbush differ widely in their habitat and 

associates. Shadscale (Atriplex confertifoMa) is a well-known and 

widely distributed desert plant that generally depends directly on the 

moisture from rain and snow and apparently has little tendency to 

utilize ground water except possibly in certain localities.

In his catalog of plants in the Salton Sink, Parish 90 lists eight 

species of APriplex, three of which he describes as growing in damp 

or wet soil, evidently signifying moisture due to rising ground 

water. These are Atriplex lentiformis, Atriplex pofycarpa, and 

Atriplex cctmescens. He describes them as growing on the extensive 

alkaline flats that stretch from Indio to the borders of the Salton 

Sea, near Mecca, in association with Dondia torreyana .and AllenTolfea occidentals. He states that over much of the area the water 

table is sufficiently high to permit the capillarity of the soil to raise 

the water nearly or quite to the surface. He further states that 

these five species do not grow intermingled, or at most are intermingled only on the borders of the portions respectively occupied by 

each, the Dondia and Allenrolfea occupying the most alkaline soil. 

He describes the three species of Atriplex and their occurrence as 

follows:

The three species of Atriplex above named hold possession of the larger 

part of this area, their distribution being determined by the amount of water 

in the soil. Those parts in which the water content is greatest is occupied by 

Atriplex lentiformis. This is a vigorous species with leaves broader and 

greener than those of the others. It grows either in thickets close as a hedge, 

or isolated in great domes, 6 to 8 feet a.nd exceptionally even 12 or 15 feet in 

height and base diameter. The same requirement of a very damp soil is 

manifested elsewhere in its position about springs and on river banks.

Where the soil is somewhat drier Atriplex polycarpa forms a nearly pure 

stand. Its habit of growth is similar to that of Atriplex lentiformis, but 

mostly in thickets and less frequently in dense entangled individuals, in neither 

case much over 3 feet in height.

The third species, Atriplex canescens, has great ecological adaptability, so 

that while reaching its best development on the drier margins of these flats, 

it also is frequent in the most arid soils.

80 Parish, S. B., op. cit., pp. 92, 93, 107, 108.
PBINCIPAL 'SPECIES 33

The occurrence of several species of Atriplex and their relation 

to seepweed (Dondia torreyana) in the Santa Cruz Valley, near 

Tucson, Ariz., are described by Spalding 91 as follows:

In the lowest part of the salt spots, where the drainage is most defective, 

Suaeda moquinii [Dondia torreyana] is characteristic and in some cases is 

well nigh exclusive in its occupation of the soil. Commonly, however, there 

are associated with it a few other plants, especially one or more species of 

Atriplex. Thus, Atriplete lentiformis grows luxuriantly, even where the socalled black alkali, chiefly sodium carbonate, forms a heavy crust, and both 

Atriplex nuttallii and Atriplex elegans are of frequent occurrence in low spots 

where the accumulation of alkali has reached a high percentage.

Beyond this association, and outside of it, Atriple® canesoens, in many cases, 

is conspicuously present. Its range, however, extends over the flood plain 

and even beyond it, so that although closely related genetically, it can not 

be referred to the more restricted association of saltbushes, which have the 

salt spots as their habitat. Thus a zonal arrangement, often well marked, is 

produced, in which the center may be quite bare of plants, while around it, in 

successive concentric zones, are (1) Suaeda moquim and Atriplex nuttallii, (2) 

Atriplex polyoarpa, (3) Atriplex canescens and various other species which 

belong around or outside the limits of the salt spot proper.

Atriplex ccmescens is described by Kennedy 92 as " a robust, shrubby 

perennial from 4 to 10 feet high, native of the high valleys and 

plains of Wyoming, Nevada, Arizona, New Mexico, and western 

Texas. * * * It has proved its adaptability to soils impregnated 

with white alkali and also withstands small amounts of black alkali. 

Its resistance to cold adds greatly to its value."

In Tularosa Basin, N. Mex.,93 a lowland area of about 650 square 

miles has as its dominant vegetation a saltbush, presumably Atriplew 

canescens^ which is known by the Mexican inhabitants as 

chamiso but is often incorrectly called " sagebrush" by the 

English-speaking settlers. The soil throughout this chamiso zone 

consists largely of gypsum but as a rule contains only moderate 

amounts of alkali, although in some places the alkali content is large. 

In 19 localities of chamiso that were investigated the depth to the 

water table was determined in 8 and estimated in 11 localities. In 

the 8 localities the depth to the water table ranged from 13 to 62 feet; 

in the 19 localities it ranged, according to the estimates, from 8 to 62 

feet. In 2 localities it was 10 feet or less, in 4 it was between 10 and 

20 feet, in 8 it was between 20 and 30 feet; in 2 it was between 30 and 

40 feet; and in 1 each it was 45, 60, and 62 feet. In 3 of the localities 

chamiso was associated with pickleweed, and in 8 it was associated

91 Spalding, V. M., op. cit., p. 13.

92 Kennedy, P. B., Saltbushes: U. S. Dept. Agr. Farmers' Bull. 108, p. 12, 1900.

83 Melnzer, 0. E., and Hare, R. F., op. cit. (Water-Supply Paper 843), pp. 193-199, 

306-311.

M Coville, F. V., and MacDougal, D. T., Desert Botanical Laboratory of the Carnegie 

Institution: Carnegie Inst Washington Pub. 6, pp. 5-8, 1903.
34 PLANTS AS LNTDICATOKS OF GEOUND WATER

with mesquite. In general the chamiso belt is bordered on its lower 

margin by the belt of pickleweed and salt grass and on its uppeo?

.Zone in which chamiso 

H is dominant yegeta- 

'_ tion, except in certain localities where 

if. water table is near 

r surface and where 

salt grass and pickleweed are dominant

R.IO E. 

lO Miles

PIQUBB 6. Map of a part of the east slope of Tularosa Basin, N. Mex., showing 

areas in which mesquite Is the dominant plant and their relation to ground water. 

In general chamiso is the dominant plant on the lower or west side of the mesquite areas and creosote bush on the upper or east side. (After Meinzer, 0. E., 

and Hare, R. F., op. cit. (Water-Supply Paper 343) pi. 2)

margin by the mesquite belt. In parts of the east side of the basin 

the belt of dominant chamiso extends up to the region where the
PBIFCIPAL SPECIES 35

R. 5 E.

depth to the water table is about 30 to 35 feet, but there are many 

exceptions to this rule, and in some places it extends above the 50-foot 

line. (See fig. 6.) On the west side the relation of this belt to the 

depth to the water table is still more irregular and complicated, as is 

shown in Figure 7. In general it is bounded on the upper side by 

the mesquite belt, but in the interstream areas, where the soil is 

doubtless more gypseous 

than in the areas that 

are periodically flooded 

by storm waters from 

the mountains, the mesquite belt may be interrupted and the chamiso 

may extend as the dominant vegetation up the 

alluvial slope, beyond 

the line where the depth 

to water is 100 feet, and 

may be dominant in 

tracts above the mesquite 

belt. In some of the 

smaller basins of central 

New Mexico chamiso is 

found, as in the Tularosa 

Basin, on the lowland 

tracts that have only 

moderate depths to 

water but are especially 

noteworthy for their intensely gypseous soils. 

Obviously this species is 

well adapted to a gypseous soil, and its occurrence in these basins is 

largely controlled by 

the distribution of this 

soil.

In Sulphur Spring Valley, Ariz., a saltbush called chamiso 

(species not definitely determined but presumably Atripless ccwescens) 

is found to a moderate extent in the shallow-water area, chiefly in 

association with alkali sacaton between the burroweed-saltgrass belt 

on the lower side and the mesquite belt on the upper side. In five 

localities that were studied in which chamiso was growing the 

observed or estimated depth to the water table ranged from 8 to 25

FIGURE 7. Map of a part of the west slope of Tularosa 

Basin, N. Mex., showing belts of vegetation and 

their relation to ground water. Numbers on dashed 

lines indicate depths to the water table in feet. 

(After Meinzer, O. E., and Hare, R. F., op. cit., 

flg. 46)
36 PLANTS AS INDICATOES OF GEOUND WATEE «

feet, and in three of them from 10 to 20 feet. The chamiso was 

associated with alkali sacaton in all five localities, with mesquite 

in two, and with Mexican salt grass in two. The chief interest in 

the chamiso of this valley lies in the fact that the soil is not gypseous 

but contains black alkali (sodium carbonate and sodium bicarbonate). 

In the five localities the amount of alkali in the soil ranged from 

rather low to moderately high. In all three localities of which 

the soil alkali was analyzed there was found to be black alkali with 

an absence of gypsum at each depth that was sampled.

In the Tularosa Basin the chamiso is estimated to cover about 650 

square miles, or more than 400,000 acres. According to evidence 

of several kinds, the rate of recharge of ground water in this 

basin is relatively not very great. More or less discharge of ground 

water obviously occurs over an area of 150 to 200 square miles in 

which the ground water rises by capillarity virtually to the surface. 

Moreover, the mesquite almost certainly disposes of considerable 

quantities of ground water. It seems probable, therefore, that if the 

chamiso feeds on ground water in this basin it draws very sparingly 

on this supply. Apparently it utilizes water from the zone of 

saturation in some localities but is not a reliable indicator of ground 

water.

The tall, shrubby saltbush (Atriplex torreyi), which occurs in 

Utah, Nevada, and California, was found in a few localities in the 

shallow-water areas of Big Smoky, lone, and Clayton Valleys, Nev.,95 

but at no place is it the dominant plant. From the field observations 

in Big Smoky Valley the conclusion was reached that this species 

can endure considerable alkali and is generally found in low places 

having more than an ordinary supply of moisture, but that it is not 

a reliable indicator of shallow ground water. In lone and Clayton 

Valleys, however, its relations seem to be those of a true groundwater plant. Its occurrence in lone Valley is described as follows: 96

The area of ground-water discharge at the mouth of lone Creek is obviously 

due to rock formations that hem in the outlet and bring a part of the underflow to the surface. Capillary discharge is taking place in the wide Pleistocene 

stream valley from Black Spring to a point about 2 miles farther up the 

valley. The position of the water table is shown by Black and Warm Springs, 

and more precisely by the small stream which in October, 1913, rose about 

one-half mile above Warm Spring in a recently cut gully and was supplied 

entirely by ground-water seepage. From Black Spring to about the point where 

the small stream rises the surface contains crusts of alkali and black stains 

of sodium carbonate, and the vegetation consists chiefly of salt grass, rabbit 

brush, big greasewood, and the tall saltbush (Atriplex torreyi). Near Warm 

Spring the gully is only about 5 feet deep, and in October, 1913, water was 

drawn to the surface by capillarity. Near the source of the stream the gully

^Meinzer, O. E., op. cit. (Water-Supply Paper 423), pp. 96, 99, 100, 145. 

« Idem, pp. 99, 100.
PBIKCIPAIj SPECIES 37

was about 9 feet deep, and the capillary water rose only to a level 3 feet below 

the surface, but some salt grass was growing in this place. Up the valley from 

this point the evidences of shallow water gradually disappear. Five miles 

above Warm Spring the ground in the stream valley was dry, but the vegetation 

consisted of big greasewood, the tall saltbush (Atriplex torreyi) , and a small 

amount of rabbit brush. These plants are somewhat ambiguous as indicators. 

They probably draw on the ground-water supply, but may owe their presence 

to floods, the evidences of which were very distinct in the stream valley. A 

few miles farther upstream these species give way to Atriplex confertifolia, 

which predominates also on the dry bench lands.

Since the investigation in lone Valley was made, much has been 

learned in regard to the behavior of ground-water plants, and it now 

seems altogether probable that the greasewood and rabbit brush at 

the locality 5 miles above Warm Spring feed on ground water and 

that the saltbush does likewise.

The occurence of Atripleos torreyi in Clayton Valley is described 

as follows: 97

Outside of this zone in the part of the valley south of the playa there 

is a zone in which iodine weed, big greasewood (Sarcobatus vermiculatus), 

the tall shrubby saltbush (Atriplex t&rreyi), and the common spiny saltbush 

(Atrvplex confertifolia) are associated. * * * Outward from this area, 

in the direction of the mountains, first the iodine weed and then the big 

greasewood and Atriple® torr&yi disappear or become scarce, while the 

common saltbush (Atrlplex confertifolia), often called shadscale, becomes 

dominant. Over the extensive gravelly and arid tracts of the middle and 

upper parts of the alluvial slopes this saltbush maintains its supremacy.

GREASEWOOD

The shrub known as big greasewood (Scurcobatm vermiculatus) 

is one of the most conspicuous and widely distributed of the desert 

bushes in Nevada and Utah and in adjacent States, especially to 

the north. According to Coulter 98 it is "common in the Great 

Basin, and to the upper Missouri, headwaters of the Platte, and 

southward." It should not be confused with the creosote bush 

(CovUlea tridentata), which is commonly though incorrectly called 

greasewood in southern California and in Arizona, nor with the 

seepweed (Dondia), which is also sometimes called greasewood. 

It is an erect scraggy, leafy bush, 1 to 8 feet high, and has a vivid 

green color that contrasts strongly with the gray hues of shadscale 

and sagebrush. (See fig. 8.)

Greasewood was not at first regarded as an indicator of ground 

water, because to a large extent it grows on land that lies some 

distance above the water table. The information now at hand, 

however, makes it practically certain that greasewood habitually

OT Meinzer, O. E., op. cit. (Water-Supply Paper 423), p. 145. 

98 Coulter, J. M., op. cit., p. 312.,
38 PLANTS AS INDICATORS OP GROUND WATER

sends its well-developed taproot to considerable depths to reach the 

water table or the overlying capillary fringe, and that it is a true

-30

FIGUKB 8. Big greasewood (Saroobatm vermdoulatus). A, Detail showing the narrow, rather fleshy leaves; B, a plant, showing the excellent root development. The 

large, deeply penetrating taproot is characteristic of the species. (After Kearney, 

T. H., and othei^, op. cit., fig. 10)

ground-water plant not only where the water table is very near the 

surface but also in its favorite position surrounding a shallow-water
PRINCIPAL SPECIES 39

tract. It is, thus, one of the most trustworthy of all ground-water 

indicators. It has been recognized as such an indicator in many 

western valleys, especially in Nevada and Utah. In their recent 

publication Aldous and Shantz" state that the species is limited 

to subirrigated alkali lands throughout the West.

In some places the big greasewood spreads meagerly to upland 

tracts that are wetted by storm waters, but it should not be confused with the little greasewood (Sarcobatus bcdleyi), which is not 

at all a ground-water plant. The little greasewood is commonly 

associated with shadscale (Atriplew confertifolia) on arid slopes 

and plains that lie too high above the water table to be influenced 

by ground water. Its appearance is extremely dry and lifeless, 

especially during the long autumn drought.

In Big Smoky Valley, Nev., the big greasewood is abundant in 

the shallow-water areas, in great mounds on the barren playas 

(pi. 4, <7), in the sand hills in or near the shallow-water areas, andin a belt between the shallow-water areas and the extensive upland 

areas of shadscale and little greasewood, generally where the depth 

to the water table is less than 50 feet. (See fig. 9.) An interesting occurrence is on the mounds in the flat, barren, clayey, 

alkaline, and periodically submerged playa. These mounds have 

a sandy soil that was captured by the greasewood from the 

wind-borne materials. They have been gradually built to their 

present large dimensions by this process of wind deposition. The 

development of the mounds has produced favorable conditions for 

the greasewood, and the growth of the greasewood has tended to 

preserve and further develop the mounds.

In 19 localities of big greasewood that were studied in Big Smoky 

Valley the greasewood occurred alone in 3 localities and was 

associated with rabbit brush in 9, with salt grass in 7, with shadscale in 6, with sagebrush in 4, with Atriplese torreyi and iodine 

weed in 2 each, and with willow in 1. It was, of course, associated 

with the salt grass in the localities of shallowest ground water and 

with the shadscale chiefly in the upper part of the greasewood zone 

or somewhat above the zone of dominant greasewood.

The conditions as described for Big Smoky Valley agree closely 

with those found in Tooele Valley, Utah, which are set forth as 

follows: *

The area occupied by the greasewood-shadscale association forms an Interrupted belt across the valley between the areas occupied by the shadscale association and by the grass flats, respectively. It also covers the low ridges and hum* 

mocks which alternate with the basinlike depressions and flats near the shone

89 Aldous, A. E., and Shantz, H. L., op. cit, p. 110. 

1 Kearney, T. H., and others^ op. cit., pp. 400-405.
40 PLANTS AS USTDICATOBS OF GBOI7]$rD WATBB

EXPLANATION

Zone in which salt grass (Distichlis 

spicata), samphire (Allenrolfea 

occidentalis), and other ground-water 

plants are dominant. Water table 

within 10 feet of the surface

Zone in which big greasewood 

(Sarccbatus vermioulatvs) 

is dominant

Edge of 

Mountain area

Springs Approximate depths to 

water table in feet

Eleva4ted parts of the valley in 

which shadscale (Atriplex cmfertifdia) and little greasewood (Sarcobatus baileyi) 

are dominant

FIGUEB 9. Map of a part of Big Smoky Valley, Nev., showing zones of vegetation

of Great Salt Lake. In general it occupies all areas where the water table is 

sufficiently high to make moist soil accessible to the deep-rooting greasewood 

and where at the same time 1 or 2 feet of the surface soil are sufficiently dry
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 3

A. AREA OF SHALLOW GROUND WATER IN SOUTHEASTERN CALIFORNIA 

WITH GROWTH OF SALT GRASS AND SCATTERED MESQUITE

Photograph by John S. Brown

B. CUT BANK OF SANTA CRUZ RIVER NEAR TUCSON, ARIZ., SHOWING THE 

DEEP ROOTS OF MESQUITE

Photograph by V. M. Spalding (Carnegie Inst. Washington Pub. 113, pi. 3,1909)
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 4

A CLUMP OF MESQUITE, SHOWING ROOTS REACHING DOWN TOWARD 

WATER TABLE, WHICH IS JUST BELOW THE LOWLAND PLAIN

B. MESQUITE AT FOOT OF CLIFF, SHOWING CONTRAST WITH DESERT WHERE 

IT SUPPORTS ONLY SPARSE GROWTH OF VEGETATION THAT DOES NOT 

FEED ON GROUND WATER

Photographs by D. G. Thompson

C. GREASEWOOD OCCUPYING WIND-BUILT MOUND ON THE OTHERWISE BARREN PLAYA OF BIG SMOKY VALLEY, NEV.
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 5

A. VEGETATION OF THE MESQUITE ZONE SURROUNDING THE AREA OF SHALLOW GROUND WATER IN SULPHUR SPRING VALLEY, ARIZ.

B. CLUMPS OF MESQUITE (LARGE DARK PATCHES) IN MOHAVE DESERT, NEAR 

DAGGETT, CALIF., INDICATING GROUND WATER WITHIN REACH OF THE 

MESQUITE ROOTS

Photograph by D. G. Thompson
U. S. GEOLOGICAL SURVEY WATER-STJPPLY PAPER 577 PLATE 6

MOHAVE RIVER VALLEY NEAR BARSTOW, CALIF., SHOWING MESQUITE AND 

POPLAR TREES SUPPORTED BY GROUND WATER

Treeless upland in background. Photograph by D. G. Thompson

B. RUNNING MESQUITE IN AREA OF SHALLOW GROUND WATER NEAR SHAVER 

WELL, IN THE DESERT REGION OF SOUTHEASTERN CALIFORNIA

Photograph by John S. Brown
SPECIES 41

to permit the growth of shadscale. Where the water table is too low this association gives place to the pure shadscale. On the other hand, as the soil 

becomes wet nearer and nearer the surface the shadscale gradually disappears, 

and at the edge of the grass flats greasewood associates with Allenrolfea occidentaUs and Suaeda moquinU instead of with Atriple® confertifolia. * * *

Greasewood (Barcobatus vermiculatus) grows in a greater variety of habitats 

than any other flowering plant of the Tooele Valley. It was found in one place 

or another in company with the dominant species of all of the leading associations. In much the greater part of its range in the valley greasewood is associated with shadscale, but there are exceptions to this rule. The largest and 

thriftiest-looking greasewood plants grew on the summits of dunes of pure 

sand, together with sagebrush, juniper, and other characteristic plants of the 

sand-hill mixed association. Shadscale is abseflt from this community. At 

the other extreme greasewood occurs in company with Allewrolfea, in land 

which is too wet and saline for the growth of shadscale. * * *

The growth of greasewood on the sand hills makes it evident that this plant 

is not an infallible alkali indicator, although in the great majority of cases its 

occurrence is associated with an excess of salts in the soil, and in its ability to 

endure the presence of alkali it is surpassed by few other flowering^fiants. A 

condition which is almost always correlated with the presence of greasewood is 

a permanent supply of moisture available for growth within the depth of soil 

penetrated by its roots.

In Owens Valley, Calif., Lee 2 found greasewood and rabbit brush 

dominant in a belt in which the water table was from 8 to 12 feet 

below the surface and associated with salt grass where the depth to 

water was between 4 and 8 feet.

In Steptoe Valley, Nev., the data obtained indicate that in general 

greasewood occupies tracts where the depth to the water table is 

between 12 and 20 feet. (See fig. 10.) In 19 localities in Big Smoky 

Valley, Nev., in which greasewood was growing the measured or 

estimated depth to the water table ranged from 2.7 to 33 feet, except 

in one locality where the depth was estimated at 60 feet. The depth 

was less than 12 feet in 8 localities, between 12 and 20 feet jn 7 

localities, and between 20 and 33 feet in~3 localities. In prospecting 

for water in the early days in the gulches near Tonopah, Nev., the 

presence of greasewood was considered ofte of the most favorable 

indications of water. Its roots were found to go to depths of more 

than 20 feet, and, according to some reports, as much as 40 feet, to 

get ground water. Near Grandview, Idaho, H. T. Stearns observed 

roots of greasewood penetrating the roof of a tunnel 57 feet below the 

surface. Obviously a species which is able to endure desert conditions 

while it sends its roots so deep to find water will spread somewhat 

beyond its ground-water limits, and it may be expected that a scattered growth of stunted greasewood will be found in places where 

the water table is not within reach of this species.

2 Lee, C. H., op. clt. (Water-Supply Paper 294), p. 77; Am. Soc. Civil Bng. Trans., vol. 

78, pp. 232, 238, 250, 1915.
42 PLANTS AS INDICATORS OF GBOUND WATEE

R.63E. R.64E.

R.63E. R.64E.

SMILES

EXPLANATION

Grass land (chiefly salt grass) Zone in which rabbit Zone in which big Lines showing depth to 

and some barren alkali land bush is dominant greasewood is dominant water table, in feet

FIGUEE 10. Map of a part of Steptoe Valley, Nev., showing zones of vegetation an«l 

their relation to the water table. (After Clark, W. 0., and Riddell, C. W., op. cit. 

(Water-Supply Paper 467), pi. 2)

MESQUITE AND ASSOCIATED PLANTS

Mesquite has been studied in a number of localities with more or 

less reference to its relation to ground water. These studies make it
PRINCIPAL SPECIES 43

clear that mesquite is essentially a deep-rooting plant which, under 

favorable conditions, has a capacity for tapping the ground-water 

supply even where the water table' is as much as 50 feet below the 

surface; also that it has excellent adaptations for obtaining water 

from other sources and for resisting drought, as is obviously necessary if individual seedlings are to survive while they are sending 

their roots to such great depths. On account of these characteristics 

the mesquite spreads to some extent to the uplands where the ground 

water lies too far below the surface to be reached even by these 

deep-rooting plants. In the upland areas, however, its growth is 

generally scattered and stunted, except in localities -with unusual 

water supplies from other sources, and the experienced observer can 

distinguish these occurrences more or less successfully from the localities where it feeds on ground water. Localities where mesquite 

indicates ground water are shown in Plates 3, B, 4, J., #, and 5 to 7.

The common mesquite occurs in several closely related forms 

(Prosopis juUflora, Prosopis velutina, etc.). Distinct from these is 

the screw bean or screw-pod mesquite (Prosopis odorata or Prosopis 

pubescens, recently classified as Stromboc(wpa odorata or pubescens) .3 

Brown 4 states that in the Salton Sea region of California the socalled " running mesquite " (Prosopis juUflora) is considered more 

reliable as an indicator of ground water than the^crew bean. However, J. J. Thornber, writing from Tucson, Ariz., states that the 

screw bean is typically a ground-water plant, being found only in 

rich valley soils where the roots can reach water; in this respect it 

differs from Prosopis velutina.

Ball B states that water can usually be obtained at slight depths 

where mesquite is growing.

Mendenhall 6 states that mesquite may depend either on ground 

water or on the water from periodical flooding, and that where its 

growth is due to ground water the water may lie within a few feet 

of the surface or be as much as 50 feet below.

The description by Spalding 7 of the mesquite forest association 

on the flood plain of Santa Cruz Eiver near Tucson, Ariz., contains 

so much valuable information and so much critical discussion that 

the following extensive quotation from it appears justified. The 

mesquite association includes two species of acacia besides several 

other plant species. The distribution of mesquite in an area that 

was investigated just west of Tucson is shown in Figure 11.

8 For a discussion of the different species of mesquite, see Sudworth, G. B., op. cit., 

pp. 362-367. See also Tidestrom, Ivar, op. cit., pp. 286, 287. 

* Brown, J. S., op. cit., p. 114. 

"Ball, S. H., op. cit. (Bull. 308), p. 22.

6 Mendenhall, W. C., op. cit. (Water-Supply Paper 224), p. 20.

7 Spalding, V. M., Distribution and movements of desert plants: Carnegie Inst. Washington Pub. 113, pp. 9-12, 1909/

54386 27 4
44 PLANTS AS INDICATORS OF GROUND WATER

The dominant species [on the flood plain of Santa Cruz River near Tucson, 

Ariz.] is the mesquite (Prosopis), here in the form of velutina. * * * It 

is by preference a plant of low flats, though it occurs far beyond these on the 

uplands, in situations where a sufficient water supply is obtainable. In the 

neighborhood of Tucson the mesquite ranges in size from a mere shrub a few 

feet high to a tree 2 feet or more in diameter and upward of 40 feet in height. 

Such trees grow thickly on the bottom land near the old mission of San Xavier, 

forming the fine forest that stretches for miles up the river, in the shade of 

which grows a rank vegetation similar to that of eastern mesophytic forests 

in luxuriance.

The habits of the mesquite are popularly well known, and its presence is 

taken to indicate a good water supply. Its roots extend widely to a distance 

of 50 or 60 feet, according to credible observers, and possibly to as great depth;

f

TTTCSOBTjUy 

c***7-*x&y\_

^'^fjQt 

cows*"5 sr=L.

EXPLANATION

Small plants growing singly 

or in small clumps, very wloely scattered or rare

^^i_

CarUoter interval so feettdatam, s

FIGUEB 11. Map of a locality near the Desert Laboratory, Tucson, Ariz., showing 

approximate distribution of mesquite (Prosopis velutina). Lines are contours of 

the land surface shown in feet above sea level. (After Spalding, V. M., Carnegie 

Inst. Washington Pnb. 113, pi. 18, 1909)

and when cut green its wood tissue, which is hard and heavy, carries a large 

percentage of water, precisely as do the hardwoods of the eastern United 

States, and strikingly different from the creosote bush, its near neighbor on 

the slopes beyond the flood plain. At the same tune the general structural 

peculiarities of the mesquite are xerophytic. It is commonly armed with 

spines, and its coriaceous leaves are well protected against excessive transpiration. It is a plant requiring a better supply of water than many of its 

associates, yet well adapted to the low relative humidity of the desert air, and 

its occurrence beyond its own special area, ranging as it does to the top of 

Tumamoc Hill, in spots where a soil retentive of moisture affords the conditions it needs, corresponds with this peculiarity. Thus it is, in a sense, a 

desert plant, yet one of high water requirement characteristics which it shares 

with various other species. * * * s
PRINCIPAL SPECIES 45

Associated with the mesquite are a number of characteristic species, some 

of which are confined to the flood plain, while others extend with it beyond 

these limits. Of the latter Acacia constricta is a conspicuous representative. 

Its habits are essentially those of the mesquite as to water requirements, and 

it closely resembles this species in its xerophytic structure. The two grow 

side by side near the river and to the summit of Tumamoc Hill, in precisely 

the same situations, one being, apparently, the ecological equivalent of the 

other. Other species behave differently. Acacia greggii grows with the mesquite in its lower range but not on the hill above, and the same is true of 

Condalia lycioides [buckthorn]. Both of these exhibit distinctly xerophytic 

structures, but both are as yet adapted to a somewhat more restricted range 

of soil conditions than are the mesquite and Acacia constricta. Sambuous 

mexicana [elderberry] and Fraainus velutina [leather-leaf ash], also of this 

association, are still more limited in their range, growing near irrigating 

ditches, hardly affecting even the edge of the mesa-like slopes, and structurally 

are to be thought of as essentially mesophytic. * * *

It appears, then, that the flood plain is the natural habitat of ,a number 

of species, many of which are incapable of successful growth elsewhere, while 

a few grow fairly well, but not at their best, under different conditions beyond 

these limits. Taken as a whole, the plants of the flood plain find there their, 

real home, and they exhibit such of them, at least, as have been carefully 

observed with reference to this a striking conformity of the root system to 

the peculiarities of the soil in which they are growing. This, as already stated, 

is of fine texture, retentive of moisture, and of great depth, with the water 

table varying in level, but apparently never beyond the reach of the long 

taproots of the mesquite and Acacia.

The root system of these plants consists of a taproot which grows rapidly 

downward and when developed is always within reach of a permanent, deep 

water supply, and a system of widely spreading lateral roots which are in 

relation to more superficial layers of the soil. Thus the plant is admirably 

fitted to absorb water largely from the upper layers when these are moist, 

and at the same time, and also in times of drought, without any interval of 

precarious supply, to draw on the deeper sources below. The contrast between this and the shallow root system of many of the great trees of eastern 

mesophytic forests, familiar to everyone who has seen them uprooted by heavy 

winds, is highly instructive. There is little wonder that the mesquite and 

Acacia constricta have tenaciously held their places through all vicissitudes 

and promise to be dominant in their habitat until actually rooted out.

Cannon,8 in a paper published two years later, confirms the observations of Spalding and states that mesquite forms stunted, irregular bushes in its scattered growth on the uplands near Tucson, but 

that on the flood plain of Santa Cruz River, its proper habitat, it may 

become a tree 50 feet high. He states that where the mesquite grows 

large the perennial supply of water or zone of saturation, is near 

the surface, and that away from the river, where the water table 

is nearest the surface, toward either side of the flood plain, in the 

direction of increasing depth to ground water, the mesquite becomes progressingly smaller, until at the edges of the flood plain, 

where the water table is deepest, it is little more than a large bush.

8 Cannon, W. A., Root habits of desert plants: Carnegie Inst. Washington Pub. 131, 

pp. 80-81, 1911.
46 PLANTS AS LNTDICATOKS OP GEOUND WATER

He observed roots of mesquite at a depth of 16 feet and obtained 

reliable evidence of roots that went to a depth of 26 feet. He also 

states that the ranchers of southern Arizona regard mesquite as an 

indication of the presence of ground water and sometimes follow 

its roots in digging wells. In another paper, published in 1913, 

Cannon shows that the root system of mesquite, as well as its form 

above the surface, is related to the depth to the water table, and 

reaches the conclusion that mesquite assumes the tree form where 

the soil is readily penetrated and the water table is not more than 

50 feet below the surface.9

In Sulphur Spring Valley, Ariz.,10 which was investigated in 

1910, observations were made on the relation of mesquite to ground 

water. It was found that mesquite commonly ranging from 5 te 

10 feet in height, but in some places reaching a height of 15 feet, waa 

dominant in ai zone that lies on the middle and lower parts of the 

alluvial slopes. The limits of this zone are as a rule well defined,, 

.although in some places, especially on the upper side, they are 

indefinite. Exclusive of the tracts of scattered mesquite on the 

upper slopes, this zone covers about 250 square miles, or nearly onesixth of the valley surface. It is wide on the broad gentle slopes that 

descend from the large mountains, but narrower on the abrupt slopes 

bordering the smaller ranges, and in some localities it wedges out 

entirely. The inner boundary of the mesquite zone is in most places 

within the belt in which the depth to the water table ranges between 

15 and 25 feet, the poorly drained alkaline clay soil of the shallowwater tract being uncongenial for the growth of mesquite. The outer 

boundary of the zone bears a general though indefinite relation tothe depth to ground water and is in most places not very far on one 

side or the other of the line where the depth is 50 feet. (See fig. 12.)

Mesquite was found in 37 localities in Sulphur Spring Valley 

that were studied with respect to vegetation, soil, and ground-water 

conditions, in 21 of which the depth to the water table was ascertained and in the remaining 16 estimated. In the 37 localities 

the depth to the water table ranged from 11 to 50 feet. In 9 localities the depth was less than 15 feet, but in virtually all of these the 

mesquite was scattered or stunted; in 11 the depth was between 15 

and 25 feet and the growth generally luxuriant; in 10 the depth was 

between 25 and 35 feet and the growth generally luxuriant; and in 7 

the depth was between 35 and 50 feet, in 4 of which the growth was 

small or scattered. A little mesquite also occurs in localities not 

specifically investigated in which the depth is more than 50 feet. 

These data indicate that in this valley the most favorable conditions 

are found in the zone where the depth to the water table is

9 Cannon, W. A., Sorde relations between root characters, ground water, and species 

distribution: Science, new ser., vol. 37, pp. 420-423, 1913.

10 Meinzer, O. E., and Kelton, F. C., op. cit. (Water-Supply Paper 320), p. 183, pis. 1, 2.
PRINCIPAL SPECIES 47

R. 23 ET. R.24E. R.25E. R.-26E.

EXPLANATION

Barren playa Zone in which saltbudi 

(Atriplex eaneseens), 

alkali sacaton, salt 

grass, and seepweed 

are dominant

Zone in which sagebrush 

(Artemisia filifolia) is 

dominant

Zone in which mesquite 

is dominant Lines showing depth 

to water table, in feet

FIGURE 12. Map of a part of Sulphur Spring Valley, Ariz., showing zones of 

vegetation and their relation to the water tahle. (After Meinzer, O. E., and 

Kelton, P. C., op. cit. (Water-Supply Paper 320), pis. 1, 2)
48 PLANTS AS INDICATORS OF GROUND WATER

between 15 and 35 feet. Where the depth is less than 15 feet mesquite is associated chiefly with alkali sacaton; where the depth is 

greater than 15 feet it is associated with alkali sacaton and other 

grasses or occurs as the only prominent species.

In the Tularosa Basin, N. Mex.,11 which was investigated in 1911, 

the mesquite zone occupies the intermediate parts of the alluvial 

slopes and forms an irregular belt on each side of the basin. Within 

the area that was mapped in detail it occupies about 180 square miles, 

five-sixths of which is on the east side, where the alluvial slopes are 

gentler and the water supply larger than on the west side. Its outer 

boundary is in most places formed by the creosote zone and is generally more definite than the inner boundary, adjacent to the chamiso 

zone. On the east side (fig. 6) the mesquite zone in most places 

extends up the slope to areas where the depth to water reaches 75 to 

100 feet. Its lower boundary is obviously controlled not so much by 

the depth to water as by the occurrence of gypseous soil, which is not 

congenial to mesquite and in which it can not compete with chamiso.

On the west side (fig. 7) the relations are irregular. In the areas 

that are flooded by the principal ephemeral streams from the mountains the mesquite extends up the slope far above the 50-foot line of 

depth to water and even above the 100-foot line. These facts suggest 

that on both sides the mesquite at the highest levels maintains itself 

on flood water rather than on ground water.

Mesquite was found in 12 localities in the Tularosa Basin which 

were specifically investigated with respect to vegetation, soil, and 

water supply. In nine of these localities the depth to the water table 

was determined, and in the other three it was estimated. In these 12 

localities the depth to water ranged from 11 to 62 feet. In one locality the depth was less than 15 feet, in eight it was between 15 and 35 

feet, and in three it was more than 35 feet. In eight of these localities the mesquite was associated with chamiso.

In 1884 Havard 12 gave the habitat of mesquite as including parts 

of the United States south of the thirty-seventh parallel, particularly Texas and the Southwest, and South America to Brazil and 

Chile. He stated that the roots are of great horizontal and vertical 

extent, probably penetrating to depths of 30 or 40 or perhaps even 

60 feet, and he expressed, the belief that they usually reach the water 

table. He made the observation that the variation in the size of 

mesquite can be taken as an index of the depth to the water table, the 

largest mesquite indicating the shallowest depth.

In 1891 Coville,13 in his botanical reconnaissance in the Mohave 

Desert and Death Valley regions of California, observed the root of

11 Meinzer, O. E., and Hare, R. F., op. cit. (Water-Supply Paper 343), pp. 194, 306-311, 

1>1. 2, fig. 46.

12 Havard, V., The mesquit: Ata. Naturalist, vol. 18, pp. 450-459, May, 1884.

13 Coville, F. V., op. cit., pp. 35, 47.
ff, - .«sPRINCIPAL SPECIES 49

a mesquite which had been washed out by a torrent and which was 

about 50 feet long but apparently had not extended to a depth of 

50 feet. He states that in the Death Valley region, "where the 

hydrostatic water [ground water] is not intensely alkaline or [and] 

is situated only a few yards beneath the surface, its presence is indicated by a growth of mesquite."

In Play as Valley, N. Mex., investigated by Schwennesen and 

Hare 14 in 1913, the upper boundary of the zone of dominant mesquite is roughly determined by the 50-foot limits of the water table, 

but the lower boundary is less definitely related to the depth to water 

and is apparently determined by the occurrence of alkaline and 

clayey soil, which is poorly drained and difficultly penetrated by the 

taproots of the mesquite. (See fig. 13.) Mesquite was found in 

27 localities in Playas and adjacent valleys, which were specially 

I studied and for which the depth to water was determined or estimated by Schwennesen. In one of these localities the depth was 

only 10 feet, in fifteen it was between 15 and 50 feet, and in the remaining eleven it ranged from 54 to 300 feet. In general the mesquite between the 15 and 50 foot limits was luxuriant, and that above 

the 50-foot limit was small and scattered, but in several places good 

mesquite was found where the depth to water was between 50 and 

100 feet.

Smith 15 describes the erosion of grassy bottom lands in Arizona 

that resulted from overgrazing. After the cutting of wide stream 

channels and the consequent lowering of the water table the sacaton 

disappeared, and trees, notably mesquite, took possession. Smith's 

statement continues as follows:

Where the depth to ground water is within 25 or 30 feet the trees have 

become continuous forests covering the ground. That the trees send their roots 

down to the water table is easily proved, for the caving banks of rivers and 

arroyos reveal them. The mesquite, in particular, has deep, strong taproots, 

with a generous development of feeders.

The hypothesis has been held by the writer for a long time that the water 

drawn up through trees and transpired constitutes the principal loss from the 

ground-water reservoir, and that, in some cases, this loss is the total loss, while 

in all cases evaporation is an agency of less import.

Later observations by Smith 16 indicate that mesquite will feed on 

ground water where the depth to the water table is somewhat greater 

than 30 feet.

In the lower Gila region of Arizona, which was surveyed for 

desert watering places by Eoss 17 in 1917, it was found that mesquite 

grows in a number of valleys where the ground water is certainly

14 Schwennesen, A. T., op. cit. (Water-Supply Paper 422), pp. 52, 144-149, pi. 2.

15 Smith, G. E. P., Am.. Soc. Civil Eng. Trans., vol. 78, p. 227, 1915.

16 Personal comhranication.

17 Ross, C. P., op. cit. (Water-Supply Paper 498), pp. 15, 16, 40.
50 PLANTS AS INDICATORS OF GROUND WATER

too deep to be within reach of its roots. For example, in the 

Centennial Wash, beyond the stretch where there is a definite stream 

channel, mesquite .bushes extend across the adobe plain, forming 

lines of green that join and part again in a pattern very similar to

EXPLANATION

FiG0EE 13. Map of a part of Playas Valley, N. Mex., showing zones of vegetation 

and their relation to ground water. (After Schwennesen, A. T., op. cit., pi. 2)

that produced by,the channels of a braided stream but following 

no visible channels. In the Lone Mountain well, in this vicinity, 

the depth to water is about 400 feet and careful inquiry of well 

drillers indicates that there is no perched ground water. In these 

localities of deep water table, however, the mesquite is always
PRINCIPAL SPECIES 51

stunted and poor. On the other hand, where the ground water lies 

sufficiently near the surface to be reached by the roots of mesquite 

it forms dense thickets and forests of creeping and arboreal forms, 

in some places growing to heights of 20 and even 40 feet. The 

mesquite thicket on the adobe flats of Arlington Valley, with an 

optimum depth to the water table, is described by Boss as " so dense 

that the cow punchers can not penetrate it with their horses. If 

cattle get into it they are in a sanctuary safe from pursuit until 

they wander out again."

A study of the relation of mesquite to ground water was made by 

Brown,18 in 1917, in connection with his survey of desert watering 

places in the Salton Sea region of southeastern California, including the Colorado Desert. The following table gives some of the 

data obtained by him:

Data showing relation of mesquite trees to water level 

[By John S. Brown]

Locality

Adams well, Palen Mountains .... 

Anshutz well, Eagle Mountains ..

Blair well, SE. }& sec. 24, T. B S., 

R. 6E. 

Chuckwalla well, sec. 33, T. 8 S., 

R. 17 E. 

Clemens well, sec. 31 (?), T. 7 S., 

R. 13 E. 

Cook weH, N. J£ sec. 22, T. 5 S.,

R. 6E.

T. 17 S., R. 18 E.

R. 6E. 

Harper well, sec. 26, T. 12 S., R. 

10 E. 

Indian Wells post office, sec. 24, 

T. 5 S., R. 6 E. 

Packard well, Palen Mountains ..

San Felipe town site, sec. 5, T. 13 

S., R. 10 E. 

Shaver well, sec. 27 (?), T. 6 S., 

R. 10 E. 

Sternberg well, SW. H sec. 10, 

T. 13 S., R. 10 E. 

Sec. 34 (?), T. 12 S., R. 10 E......

Sec. 33 (?), T. 12 S., R. 10 E ......

Sec. 4 (?), T. 13 S., R. 10 E .......

Palo Verde Valley _____ . ....

Desert east of Imperial Valley. ...

Depth 

to 

water 

(feet)

20 

8

34

VA 

16

75

80

70

C) 

34 

18 

27K 

21 

45 

15 

16

20

0-12

8-15

20-30

Character of mesquite growth

1 lone mesquite bush beside 

well; some others not far away 

in bed of dry wash. 

Trench cut in side of canyon 

shows roots of mesquite penetrating crevices of rock to water; small clumps of mesquite 

in vicinity. 

Abundant mesquite 10 to 12 feet 

high near by. 

Mesquite abundant locally in 

bed of dry arroyo. 

Stunted mesquite bushes locally 

in dry arroyo. 

None .........-.... ...........

.....do........ ...... ... .........

.....do.... ......................

Thick forest of trees 10 to 20 feet 

high in neighborhood. 

Abundant forests of mesquite 10 

to 15 feet high in neighborhood. 

Large patch of mesquite locally 

in bed of dry arroyo. 

Scattering growth 5 to 6 feet high 

near by. 

Plentiful clumps 10 feet high in 

vicinity. 

Scattering growth 2 to 3 feet high 

all around. 

Heavy timber of mesquite 10 to 

12 feet high. 

.. _ do. _________ . _

above.

Scattering but persistent growth 

over large strip east of old 

beach.

Nature of soil

Stream gravel.

Granite, somewhat jointed 

and sheared.

Very porous sand; forms 

dunes in neighborhood. 

Stream gravel and clay.

Gravel and clay. 

Porous sand.

Porous sand and silt.

Sandy silt.

Porous sand; forms large 

dunes in vicinity. 

Gravel and rock; well ends 

in limestone. 

Sandy silt.

Stream gravel. 

Sandy silt. 

Do. 

Do.

Do.

Porous sandy silt.

Do.

Sand and silt.

1 Flowing well; water stands in arroyo 8 feet below well.

» Brown, 3. S., op. cit. (Water-Supply Paper 497), pp. 17, 114-117.
52 PLANTS AS INDICATORS OF GROUND WATER

Brown states that in every extensive tract that is covered with 

mesquite there is a gradual dwarfing of the trees away from some 

district in which the water table is near the surface, suggesting that 

the size of the trees is a function of the depth to water, modified, 

however, by the character of the soil. This relation is shown for 

certain localities in Figure 14. Section A shows conditions in the 

Indian Wells region of Coachella Valley, where the soil is an exceedingly loose sand. It indicates a maximum depth to the water table 

of 50 or 60 feet where mesquite grows freely. Sections B and C show 

conditions in the Harper Well district, where the soil is generally 

porous sandy silt but in places is rather compact clay. These sections indicate that the maximum depth to the water table at which 

mesquite can reach ground water in this district is 40 to 50 feet. 

Section D shows the conditions between Alamo School and the new 

county well, on the east side of Imperial Valley. There is a strong 

flowing well at Alamo School. Water does not stand at the surface 

anywhere but is under artesian pressure for some distance east of the 

schoolhouse. Mesquite grows abundantly to heights of 10 or 12 

feet west of the old beach, and it covers thinly a strip 2 to 3 miles 

wide above the beach to the east but is rather stunted. The depth 

to water at the line of disappearance is probably 30 to 40 feet. The 

soil is mixed sand and clay. The subject is summarized by Brown as 

follows:

From the isolated occurrences tabulated it appears that healthy mesquite 

clumps in canyons and arroyos generally indicate water at a depth of less than 

25 feet, although stunted specimens in small numbers may not be reliable 

indicators of water. Where mesquite covers large districts water is certainly 

present at depths probably less than 50 feet in any soil and less than 30 feet 

in very compact soil. Where healthy mesquite appears in isolated localities 

there is almost certainly water within at least 30 or 40 feet, usually less than 

20 feet, of the surface. In examining carefully these isolated clumps of mesquite 

some good reason is nearly always discovered for the presence of water near the 

surface, and the mesquite is especially valuable in seeking water because it 

appears to have overlooked but few of the possible places where it might 

get a foothold.

In the survey of desert watering places in the Papago country of 

southwestern Arizona, Bryan 19 found that along Gila and Santa 

Cruz Kivers the mesquite groves undoubtedly draw a large part of 

their supply of water through the roots from the underlying water 

table, but that in the interior valleys mesquite trees and even large 

groves of mesquite exist where the ground water is from 60 to several hundred feet below the surface and seem to be dependent wholly 

on rain and flood water. He made the observation that the mesquite 

trees in the areas of deep ground water are more erect and more 

treelike than the mesq«ite of the areas of shallow ground water.

19 Bryan, Kirk, op. cit. (Water-Supply Paper 499), p. 156.
PRINCIPAL SPECIES 53

This observation appears to conflict with the observations of some of 

the other authorities that have been cited, but it agrees with what

C.£.Coot< we// /ndfanWe//sf?O.

__ _Wafer tab/e 

Above sea level

8 mi/es

B

FIGURE 14. Sections showing relation of mesquite to the water table in the Salton 

Sea region, California. A, Coachella Valley; B, C, Harper Well and San Felipe 

district; D, Imperial Valley. (After Brown, J. S., op. cit. (Water-Supply Paper 

497), fig. 10)

the writer of this paper has seen in some localities. The following 

statements by Sudworth and Smith also bear contrary evidence:

As a rule, the larger the stem above ground the smaller the root development; low, shrubby stems commonly have huge taproots descending to water 

at a depth of 50 or 60 feet or more.20

20 Sudworth, G. B., op. cit., p. 365.
54 PLANTS AS INDICATOBS OF GEOUND WATER

There seems to be a lack of relationship between the size of mesquite trunks 

and the depth to water. At Redington our experimental work is done in a 

mature mesquite forest. I say mature because the forest is so thick that the 

decay and drying up is as great as the new growth, and yet the trunks of the 

trees in no case are of very great size. It is a thick stand of small trees. On 

the other hand, on the Canoa land grant, between Tucson and Nogales, are 

the largest mesquites I have ever seen. One of them originally must have 

been at least 3% feet in diameter. The depth to ground water at that place 

is as much or more than the depth at Redington.21

In the survey of desert watering places in the Mohave Desert 

region Thompson 22 found both the screw bean and the ordinary 

mesquite (Prosopis juliflora). He describes their distribution in the 

region as follows:

The screw bean and ordinary mesquite occur together in many places. 

They are abundant in stretches along Mohave River where ground water is 

close to the surface but are absent in other stretches where the depth to water 

is considerable. They are also found in the lower parts of some of the closed 

basins and in other places where the geologic conditions hold the water table 

close to the surface. They are present in the lower parts of the basins near 

playas in Antelope Valley, in Indian Wells Valley, and in Crucero Valley along 

Soda Lake and elsewhere. They grow also in a belt that stretches northwestward from the vicinity of Newberry Spring, where a buried geologic structural 

feature brings the water to the surface.

In many places where the mesquite grows in open expanses of land windblown sand accumulates around the plants. As the plant grows the sand accumulates more and more, and dunes, sometimes 15 or 20 feet high, are 

formed. The mesquite spreads out, and the different branches, being covered 

by sand, appear to be a number of individual plants. The roots generally penetrate some distance below the original ground surface in search of water, 

although the plants may appear to be perched on top of the dunes.

On the basis of numerous observations Thompson concludes that, 

whatever may be the uncertainties of mesquite as an indicator of 

ground water in adjacent areas, in the Mohave Desert region wherever 

mesquite was observed the depth to water is not more than 25 or 30 

feet and the mesquite is generally considered to indicate that ground 

water is within that distance of the surface.

ALFALFA

Alfalfa requires a large supply of water to grow luxuriantly but 

does not generally thrive on poorly drained soil where the zone of saturation is at or very near the surface. It will send its roots to great 

depths to find water. According to Clarke,23 of the California Experiment Station, it has been known to penetrate to the depth of 12 

feet in a single season and the roots of older plants have been traced 

to a depth of 65 feet. Piper,24 of the United States Department of

21 Smith, G. E. P., personal communication.

22 Thompson, D. G., op. cit.

28 Clarke, W. T., Alfalfa: California Univ. Agr. Exper. Sta. Circ. 87, p. 1 (no date). 

24 Piper, C. V., Forage plants and their culture, revised ed., p. 362, New York, Macmillan Co., 1924.
TT. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 7

MOHAVE RIVER VALLEY NEAR YERMO, CALIF , SHOWING DUNES ON BOTH SIDES, DUE LARGELY TO MESQUITE THAT FEEDS ON GROUND

WATER

Photograph by D. G. Thompson
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 8

A. ALFALFA RAISED ON SEC. 31, T. 28 S.f R. 10 W., NEAR MILFORD, UTAH, WITHOUT IRRIGATION

The water supply was drawn from the zone of saturation by the roots. Photograph by Walter

N. White

B. THICKET OF BIRCH TREES THAT FEED ON GROUND WATER AT THE MOUTH 

OF SANTA FE CANYON, BIG SMOKY VALLEY, NEV.
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 9

A. WILLOW TREES AT HIDDEN SPRINGS IN THE DESERT REGION OF SOUTHEASTERN CALIFORNIA

The springs issue from porphyritic rock en a,hillside. Photograph by D. G. Thompson

B. WILLOW TREE AT LEACH SPRING, IN THE DESERT REGION OF SOUTHEASTERN CALIFORNIA

Photograph by H. S. Gale
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 10

A. ZONE OF TREES THAT FEED ON GROUND WATER IN MOHAVE VALLEY, 

CALIF., IN CONTRAST WITH THE DESERT AREA THAT DOES NOT SUPPORT 

GROUND-WATER PLANTS

Photograph by D. G. Thompson

B. GROVE OF COTTON WOOD TREES THAT INDICATE AN AREA OF SHALLOW 

GROUND WATER IN THE SALTON SEA REGION, CALIFORNIA

Photograph by John S. Brown
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 11

A. SEVEN PALMS, A SPRING LOCALITY IN THE DESERT REGION OF 

SOUTHEASTERN CALIFORNIA

B. PALM, COTTONWOOD, AND MESQUITE TREES IN AREA OF SHALLOW GROUND 

WATER AT CORN SPRINGS, IN THE DESERT REGION OF SOUTHEASTERN 

CALIFORNIA

Photographs by John S. Brown
U. S. GEOLOGICAL SURVEY WATER-SUPPLY PAPER 577 PLATE 12

A. LARGE PALM TREES IN AREA OF SHALLOW GROUND WATER IN 

THE ARID REGION NEAR GUANTANAMO NAVAL STATION, CUBA

B. GROVE OF PALM TREES THAT INDICATE SHALLOW GROUND WATER IN 

AN ARID PART OF SOUTHERN CUBA
PRINCIPAL SPECIES 55

Agriculture, states that the roots of alfalfa will under ordinary 

conditions descend to a depth of 6 feet and are known to have reached 

depths of 15 feet. He also states that there are less well-authenticated reports of roots 25 to 45 feet in length and one record of a 

taproot 66 feet long. S. H. McCrory,25 of the Department of Agriculture, states that at the Cheyenne Experiment Farm alfalfa roots 

were traced to a depth of 20 feet. C. W. Irish, also of the Department of Agriculture, observed the roots of alfalfa in a mine tunnel 

in Nevada at a depth of 129 feet. The tunnel was in " rotten porphyry " with crevices from which water was dripping. Through the 

crevices came also the roots, which were found to be those of 

alfalfa from a field above the tunnel.26

Recently alfalfa has been grown as a ground-water plant in various 

parts of the arid West, where the water table is within about 15 feet 

of the surface and has succeeded in recovering enough water from the 

zone of saturation to produce some hay as well as to make profitable 

crops of seed, although the growth is not nearly so good as under 

adequate irrigation.

In Estancia, N. Mex., in the immediate vicinity of which the climate 

is too arid for successful agriculture without irrigation, a small plat 

of alfalfa was observed where the water table stood about 14 feet 

below the surface. It was planted in June, 1921, and, though never 

irrigated, made a good stand and produced three crops of hay in 

1922 and four -crops in 1923. The third crop in 1923, according to 

weighings made by the owner, was equivalent to two-thirds of a ton 

to the acre. Favorable rains in 1921 started the alfalfa, but the good 

growth in the dry summers of 1922 and 1923 can not be attributed to 

rain and was undoubtedly due chiefly to the water obtained from the 

zone of saturation.

In the Escalante Desert, Utah, where the precipitation averages 

scarcely 10 inches a year, valuable crops of alfalfa seed have been 

successfully raised on a fairly large scale, as described by W. N. 

White on pages 89-91, in localities where the depth to the water table 

ranges between 6 and 15 feet. The young alfalfa is irrigated with 

water pumped from wells, but after it has established itself it grows 

and produces seed crops without irrigation. (See pi. 8, A) Alfalfa 

is also raised without irrigation in shallow-water tracts in Sacramento Valley, Calif., but much difficulty is there experienced with 

gophers, which are not very troublesome in fields that are irrigated.

Evidently alfalfa has some of the properties of greasewood and 

mesquite in that it does not thrive where the water table is very near 

the surface but, on the other hand, will send its roots to considerable

ZB McCrory, S. H. (chief Division of Agricultural Engineering, U. S. Dept. Agr.), personal communication. 

28 See Coburn, F. D., Alfalfa, p. 14, New York, 1901.
56 PLANTS AS INDICATORS OF GROUND WATER

depths in search for ground water. Much interest attaches to these 

properties of alfalfa for two reasons: First, they suggest the possibility of utilizing the great quantities of ground water that now virtually go to waste each year because of the prohibitive cost of pumping, by developing profitable ground-water plants in place of the 

worthless native species which at present consume so much of the 

ground water (p. 88); second, they suggest a new approach to the 

study of ground-water plants, especially as to the quantity of water 

consumed in relation to the dry material produced, and as to the 

quantity of the dry material produced in relation to the depth of the 

water table below the surface (p. 87).

A study of the history of alfalfa with special reference to its existence under conditions where it had to utilize ground water would 

be very instructive. It seems probable that its properties of feeding 

on ground water are not newly acquired but are rather inherited 

traits that were established long before man learned the art of 

irrigation. This is suggested by the facts that, so far as known, 

alfalfa was first cultivated in Persia and that it grows wild in parts 

of central and western Asia and in northern Africa.

WILLOW

The water-loving character of willows is recognized throughout 

humid as well as arid regions. Although the distinction between 

plants that feed on ground water and other plants can not be so 

sharp in humid as in arid regions because of the relative abundance 

of moisture in the soil above the capillary fringe in the humid 

regions, yet it is common knowledge that at least some species of 

willow prefer to live in low, moist tracts. There can be no reasonable 

doubt that even in the humid regions these willows feed largely on 

water from the zone of saturation and can therefore properly be 

called ground-water plants.

Willows also occur as ground-water plants in many desert valleys 

and have been described as such in the Mohave Desert 27 and Salton 

Sea 28 regions of southeastern California, the lower Gila region 29 of 

Arizona, several of the valleys of central and southern Nevada,30 

Pahsimeroi Valley, Idaho,31 and Goose Creek Basin, Idaho.32

27 Thompson, D. G., op. clt. (Water-Supply Paper 490-B), p. 98.

28 Brown, J. S., op. cit. (Water-Supply Paper 497), p. 17.

^Ross, C. P., op. cit. (Water-Supply Paper 498), p. 15.

80 Ball, S. H., op. cit. (Bull. 308), pp. 22, 24. Carpenter, Everett, op. clt. (WaterSupply Paper 365), pp. 13, 36, 59. Meinzer, 0. E., op. clt. (Water-Supply Paper 423), 

pp. 96, 100.

31 Meinzer, O. E., Ground water in Pahsimeroi Valley, Idaho : Idaho Bur. Mines and 

Geology Pamphlet 9, p. 27, 1924.

32 Piper, A. M., Geology and water resources of the Goose Creek Basin, Cassia County, 

Idaho: Idaho Bur. Mines and Geol. Bull. 6, p. 50, 1923.
PRINCIPAL SPECIES 57

Willows are described by Parish 33 as occurring throughout the 

Salton Sink, California, along river banks, near springs, and in 

damp soil, and by Spalding 34 as lining the banks of Santa Cruz 

River near Tucson, Ariz., in association with cottonwood trees. Two 

species of willow, jSaHos gooddingii and jSaMx fluvwtttis, are especially mentioned by J. J. Thornber as ground-water plants. He 

states that in the Gila Valley, Ariz., both at Phoenix and at Yuma, 

jSalisB gooddingii) a large tree, is the common valley willow. In Big 

Smoke Valley, Nev., willows are found in localities where ground 

water can be obtained near the surface but where the soil has some 

drainage and is not very alkaline. Their presence was recorded in 

two localities one where the depth to the water table was 6 feet and 

they were associated with salt grass; the other where the depth was 

11'A feet and they were associated with sagebrush and greasewood 

It is possible that these plants were wrongly identified and that 

they are desert willow instead of true willow. In Plate 9 are shown 

two springs in the desert region of southeastern California that are 

marked by willows.

DESERT WILLOW

The desert willow (Ghilopsis linecvns) generally indicates ground 

water, but there is evidence that in some localities it feeds on ground 

water where the water table is as much as 50 feet below the surface 

and that in others it has no relation to the water table. Coville S5 

observed the species in a number of shallow-water localities and lists 

it with true willows, under " desert plants of humid habitat." He 

is, however, somewhat ambiguous in his summary statement that 

"this plant grows near streams or springs or in their dried beds." 

Brown,36 in describing the vegetation of the Salton Sea region, California, states that the desert willow is a common tree in the dry 

washes of the desert and unfortunately ruins the reputation of true 

willows as indicators of ground water, for it apparently has no connection with permanent ground water. Thompson 37 considers that 

in the Mohave Desert region it is generally, though perhaps not 

always, found where ground water is near the surface. He states 

that although it grows in channels along Mohave River where the 

depth to water is probably not more than 25 or 30 feet it is not a 

certain indicator that the water table is close to the surface.

Bryan 38 states that in the Papago country, Arizona, the virtues 

of the desert willows, as also of the batamote (Baccharis glutmosa)

33 Parish, S. B., op. cit, p. 107.

«* Spalding, V. M., op. cit., p. 8.

35 Coville, F. V., op. cit., pp. 39, 174.

30 Brown, J. S., op. cit., p. 18.

3T Thompson, D. G., op. cit. (Water-Supply Paper 490-B), p. 98.

ss Bryan, Kirk, op. cit., pp. 156-157.
58 PLANTS AS INDICATORS OP GROUND WATER

and the cherioni or wild china tree (jSapmdits margmatus) , as indicators of water are extolled by the old settlers of the region, largely 

on the basis of supposed Papago wisdom in regard to water. He 

concludes, however, that the moisture required by these plants can be 

supplied by water stored in joints and fractures in the rocks or by 

small amounts of water held above a clay or other compact bed in 

alluvium, which is too inconsiderable to supply a well.

COTTONWOOD AND OTHER POPLARS

Cottonwood trees form one of the most familiar and grateful 

features of the arid West, where they are extensively grown as 

shade trees in villages and on ranches. The cottonwoods of the desert 

region (Papulus fremontii, Papulus wizUzeni, etc.) are commonly 

found in areas where ground water is near the surface and are true 

ground-water indicators. (See pi. 10.) They are mentioned by 

Brown, Boss, Bryan, and Thompson in their desert reports, as 

trees that live on ground water. For example, Bryan states that 

the cottonwood is a reliable indicator of shallow ground water but 

requires so much moisture that it does not grow in doubtful localities. Gregory 39 states that in the Navajo country of northwestern 

Arizona and adjacent States cottonwood usually indicates a depth 

to water not exceeding 20 feet. He observed these trees growing 

in a wash where the water table is at least 50 feet below the surface, 

however, and he explained their presence in this locality as apparently 

due to perched ground water lying nearer the surface during at least 

a part of the year. Not all species of poplars should be regarded as 

indicators of ground water. For example, the aspen, or quaking 

asp, though it prefers moist localities, is not known to depend on the 

water from the zone of saturation. It is frequently found on mountain summits and slopes but is not a feature of mountain canyons 

that contain ground water.

In Pahsimeroi Valley, Idaho, cottonwoods line the principal 

stream channels for miles down the alluvial slopes. In 1921, however, these trees had in large part died in the middle portions of 

the slopes, probably because of the diversions for irrigation, which 

were especially felt in the preceding dry years. Most of the trees 

near the mouths of the canyons, where the stream waters are most 

abundant, and in the lower parts of the slopes, where the ground 

water is within reach of their roots, are still alive.

The tall, slender, and graceful Lombardy poplars, which are so 

distinctive of the villages and ranches of many parts of the West,

89 Gregory, H. B., The Navajo country a geographic and hydrographic reconnaissance 

of parts of Arizona, New Mexico, and Utah: U. S. Geol. Survey Water-Supply Paper 380, 

p. 131, 1916.
PRINCIPAL SPECIES 59

especially in Utah, frequently receive irrigation water but appar1 

ently can also live by means of ground water. At the abandoned 

San Antonio ranch, in Big Smoky Valley, Nev., two healthy Lombary poplars and three box elders were found growing where the 

water table was about 4 feet below the surface and where a test 

showed the presence of alkali at the surface. The ranch had apparently been abandoned for a considerable time, and these trees were 

growing without attention, obviously utilizing the supply of ground 

water.

BUFFALO BERRY, ELDERBERRY, BLACKBERRY, GOOSEBERRY, 

AND HACKBERRY BUSHES, SHRUBBY CINQUEFOIL, AND WILD 

ROSES

The buffalo berry bush (Shepherdia) is a tall woody and spiny 

bush that produces edible berries. It grows widely throughout the 

northern and middle parts of the arid West, probably not everywhere as a ground-water plant. One species was found growing 

abundantly in the shallow-water areas of the north basin of Big 

Smoky Valley, Nev., and also in the adjacent mountains in some 

of the canyons that carry underflow. Wherever it was observed it 

was growing strictly as a ground-water plant. Cannon,40 quoting 

Merrill, states that in Nebraska the roots of Shepherdia attain a 

depth of 50 feet. The Shepherdia in Big Smoky Valley, however, 

grows where the water table is nearer the surface.

A shrub called " quail brush " was found by Carpenter 41 in several valleys of southern Nevada, where it grows along streams and 

in localities in which ground water is found at shallow depths. The 

technical name of this shrub is not given by Carpenter, but as it 

occurs in the warm valleys of southern Nevada it is presumably not 

Shepherdia.

Elderberry and gooseberry bushes are mentioned by Ball 42 as 

indicators of water in the deserts of southwestern Nevada and 

adjacent parts of California. He states that they are unknown in 

that region except in the vicinity of water. Elderberry and a 

species of buckthorn are mentioned by Sp aiding as confined to the 

habitat where the water table is within reach, at least of mesquite 

(p. 45). Thornber states that in Arizona the two common specie? 

of elderberry (Smribucus caerulea and Sarnibucus neomexicana) are 

invariably ground-water plants, as is also the small native .blackberry (Rubus oligispermm).

40 Cannon, W. A., Carnegie Inst. Washington Pub. 131, op. cit., p. 9.

41 Carpenter, Everett, op. cit. (Water-Supply Paper 365), pp. 13, 36, 59. 

"Ball, S. H., op. cit. (Bull. 308), pp. 22, 24.

54386 27 5
60 PLANTS AS INDICATORS OF GROUND WATER

. Cumaru, or hackberry, especially the large species, which grows 

to a height of 50 feet, was observed by Bryan 43 along mountain borders in the Papago country, where it is an indicator of ground 

water.

Shrubby cinquefoil (Dasiphora fruticosa) occurs abundantly as a 

ground-water plant in the shallow-water area of Pahsimeroi Valley, 

Idaho,44 and was not observed where the water table is too deep to 

be reached by its roots.

It is well known that roses thrive best where they enjoy an abundant supply of water, although they are also abundant as weeds in 

cultivated fields with only moderate supplies of soil moisture. The 

wild roses of the humid regions are, of course, found in a great 

variety of situations, but they grow most luxuriantly in low places, 

in many of which they doubtless obtain water from the zone of 

saturation. In the strictly arid regions they are found only near 

springs and streams or in other localities where the water table is 

near the surface.45 As they can not endure much alkali they are not 

common in the lowlands except where there is enough drainage to 

prevent accumulation of alkali. A good example is afforded by a 

spring mound in the midst of a salt-grass tract in the shallow-water 

area at the San Antonio ranch, in Big Smoky Valley, Nev., on which 

roses were found growing luxuriantly.

WASHINGTON PALM AND OTHER PALMS

The oases of the deserts of the Old World are notable for their 

palm trees. In the western part of the United States wild palms are 

found in the hot and dry region of southeastern California, chiefly 

along the margins of the Salton Basin. This tree (Washingtonia 

filamentosa) is called by Brown 46 the premier of all the water indicators in the Salton Sea region. It is an unfailing sign of a spring 

or of water that can be found by digging a few feet. Moreover, 

says Brown, the tree stands up so conspicuously, with its green head 

high in the air, perhaps 50 feet or more, that it is visible for long 

distances and makes an excellent natural signpost. (See pi. 11.) Dos 

Palmas, Seventeen Palms, Twenty-nine Palms, Thousand Palms, 

Burnt Palms, Palm Springs, Palm Wash, and Palm Canyon are all

43 Bryan, Kirk, op. cit, pp. 45, 46, 157. In Bryan's paper the large species is called 

Celtis occidentalis, and a small species, which is more widely distributed and less of a 

ground-water indicator, is called Celtis reticulata. These designations are based on 

Mearns, B. A., Mammals of the Mexican boundary of the United States: U. S. Nat. Mus. 

Bull. 56, pp. 54, 55, 1907. According to Thornber, however, the principal species of 

hackberry in Arizona is Celtis reticulata, and Celtis occidentalis is not found in that 

State.

** Idaho Bur. Mines and Geology Pamphlet 9, p. 27.

^Ball, S. H., op. cit. (Bull. 308), pp. 22, 24; Meinzer, O. B., op. cit. (Water-Supply 

Paper 423), pp. 96, 99.

*« Brown, J. S., op. cit. (Water-Supply Paper 497), pp. 112, 113, 246, 247, 271, 278.
PKINCIPAL SPECIES 61

names of watering places in this region. The shallow-water tracts 

where the palm trees grow support various familiar ground-water 

plants, such as salt grass, arrow weed, mesquite, and willow, which 

help in locating the springs or the localities of shallowest water but 

which do not attract attention .from a distance, like the palms. The 

distribution and relations of the wild palm are further described 

by Brown as follows:

It is found in most of the canyons or arroyos, particularly around the borderg1- 

 of the Salton Basin, in which water rises near the surface. It is also found at 

nearly all the artesian springs of Coachella Valley. Unfortunately, it does 

not always indicate good water; sometimes, indeed, it is found at springs of 

very bad water. But usually a healthy clump of palms means a spring of 

drinkable water. The palm does not extend to high altitudes. In the Peninsular Mountains it is seldom found more than 1,000 feet above sea level. In 

the eastern desert ranges it may extend as high as 2,000 feet. So far as 

known, however, it is absent from all the ranges near Colorado River in this 

region, probably because the water supply is too scant.

In the semiarid parts of Cuba the writer observed that large palm 

trees are growing in many of the areas of shallow ground water and 

appear to be reliable indicators of ground water (pi. 12), whereas 

the small yuraguano, or fan palm, grows on the dry limestone hills 

high above the water table. In many places banana trees evidently 

feed on ground water.

FOREST TREES

It is, of course, impossible to distinguish definitely among the 

forest trees of the humid parts of the United States and of the relatively humid mountain regions in the arid parts of the country 

those which habitually use water from the zone of saturation and 

those which do not, but it is certain that some species depend much 

more on ground water than others. Several species of birch, sycamore, alder, and live oak are examples of trees which in the forests 

of the East or South show obvious preferences for lowland tracts 

where they can utilize water from the zone of saturation, although 

they may not be confined to such tracts. Moreover, it should not be 

assumed that all species of these kinds of trees depend equally on 

ground-water supplies. For example, some species of birch seem to 

show more preference for shallow-water areas than others, and the 

different species of oak range from those that depend almost wholly 

on ground water to those that are markedly independent of the 

water table.

Trees of water-loving types show their true dependence on ground 

water at their frontiers, as it were that is, in localities of shallow 

ground water within the arid regions. For example, birch trees are
62 PLANTS AS INDICATORS OF GROUND WATER

numerous in the canyons of certain mountainous regions of central 

Nevada, and there is evidence that their occurrence indicates in large 

measure the distribution of shallow ground water in these regions. 

(See pi. 8, B.) Sycamore trees indicate the presence of ground water 

in many localities in the arid regions. In the Papago country of 

southwestern Arizona the Arizona sycamore (Platanus wrigktii) 

and the leather-leaf ash (Fraxinus velutina) may be taken as reliable 

indicators of ground water.47 Alders and walnuts feed on ground 

water in many places in the arid West. The alder Alwm oblongifolia and the walnut Juglcms 'major are mentioned by Thornber 

among the ground-water species in Arizona.

Many of the trees such as are found in the forests of humid regions 

will not, however, grow in the tight alkaline soils of the shallowwater areas in the desert lowlands. Thus the birch in Big Smoky 

Valley, Nev., and the sycamores and live oaks in Sulphur Spring 

Valley, Ariz., are confined to the well-drained upland tracts of 

ground water and are not found in the shallow-water areas in the 

low parts of the valleys. In Sulphur Spring Valley ribbons of timber, consisting of sycamore, live oak, and cottonwood, extend along 

the principal stream courses from the mouths of the canyons far 

down the alluvial slopes. Their occurrence here is obviously related 

to the relatively abundant water supplies along the stream courses. 

The forested stretches of these draws or watercourses do not, as a 

rule, have perennial streams. In most places they carry water only 

during certain seasons or at times of heavy rain and are dry for 

months at a time. In many places, however, springs and shallow 

wells indicate that they are underlain by perennial supplies of perched 

ground water. The intimate relation that exists between the forested 

portions of the draws and the areas of high-level ground water suggests that the trees are supported by these relatively permanent supplies rather than by those obtained directly from the uncertain 

floods. Along Turkey Creek, for example, the lower limit of trees 

corresponds rather closely to the lower limit of high-level ground 

water. This relation has been observed in enough places to warrant 

prospecting for shallow ground water in the forested draws in which 

wells have not yet been sunk.48

A study made by Cannon 49 of three species of oak that are characteristic of the valleys of central California showed that these 

species differ greatly in their relation to the water table. The blue 

oak (Quercus douglasii) occurs where the water table is lacking, or 

so deep as to be quite beyond the possible reach of the roots, so that

*7 Bryan, Kirk, op. cit, p. 157.

^Meinzer, 0. B., and Kelton, F. C., op. cit. (Water-Supply Paper 320), pp. 102-111, 

182,187.

49 Cannon, W. A., Pop. Sci. Monthly, vol. 85, pp. 417-424, 1914.
PBIZsTCIPAL SPECIES 63

the species is wholly dependent on soil moisture near the surface for 

its water supply. The live oak (Quercus agrifolia) occurs where 

the water table is usually 35 feet or more beneath the surface. This 

species sends out some deep roots, but has a well-developed system 

of roots within 3 feet of the surface. The roble oak (Quercus lobkta) 

differs greatly from the two other species in respect to water supply. 

It is best developed where perennial ground water lies within 10 

to 20 feet of the surface or where the soil is practically homogeneous, 

so that the ascent of capillary water is great and the roots can penetrate to great depths. If not strictly confined to moist soils, it at 

least attains its best development where the soil is moist and the 

ground water is not so deep as to be beyond the reach of its roots.

Among the conifers some of the species that depend more or less 

on the zone of saturation for their water supply are the Engelmann 

spruce (Picea en-gelmann'i) , tamarack (Larix laricina), redwood 

(Sequoia sempervirens), and big-tree sequoia (Sequoia washingtoniana). The Engelmann spruce .requires a good water supply and 

depends on ground water in many localities. A. E. Douglass has 

observed that this species has very " complacent" rings. The following statement in regard to its moisture requirements is made by 

Sudworth: 50 "

Its presence is controlled to great extent by the supply of soil moisture, 

demands for which limit its occurrence to high elevations or to land moist 

from springs, seepage, or overflow. Its lower range is" limited to moist canyons 

or to protected north slopes, while on other exposures it finds suitable soil 

moisture only at higher altitudes.

In Pahsimeroi Valley, Idaho, the limber pine (Pinus flexilis) 

covers a considerable tract in the lowland area of ground-water discharge and forms a striking feature in the otherwise monotonous 

plain. In the valley these pines are strictly confined to the area of 

shallow ground water, but in the adjacent mountains they are found 

in very different habitats. The following interesting statement is 

furnished by O. M. Mink, forest supervisor, who collected specimens 

for identification by the United States Forest Service:

These trees occur in a spring area in the middle of the Pahsimeroi Valley. 

This area is a regular bog throughout the spring and summer. The trees all 

seem to be very thrifty, and a good many of them are very old. I have 

counted the growth rings on some of the old stumps cut about 25 years ago 

and found from 160 to 175. There is still a good stand, and the larger trees 

are still living. Contrary to the usual growth of limber pine in this country 

these trees are straight, not forked and twisted. There are other stands of 

the same species in this district at different places on the high ridges, but 

this particular stand is peculiar and exceptional to the locality.

The redwood is very exacting in its requirements as to soil moisture 

but avoids swampy land. The big-tree sequoia is evidently less

w Sudworth, G. B., op. cit., pp. 80, 81.
64 PLANTS AS INDICATORS OF GROUND WATER

dependent on ground water but also prefers localities where the 

water table is within reach.51 Douglass 52 states that, roughly speaking, the big-tree sequoia depends upon soil moisture more than the 

yellow pine, and that the redwood of Santa Cruz has access to so 

much moisture and hence has such " complacent" rings that he can 

not use it in any of his tests. In an unpublished report to the National Park Service on a water supply for the Mariposa grove of 

Yosemite National Park, Kirk Bryan advised against the development of an additional ground-water supply because of the damage 

that might be done to the big-tree sequoias by lowering the water 

table. He states:

Any system of obtaining sufficient ground water would involve lowering of 

the water table by draft on the ground-water reservoir. It is noticeable that 

the sequoias are clustered at the damp and boggy places and along water 

courses. Only a few grow on hillsides and ridge tops. The trees evidently 

require larger amounts of water than many other forest trees.

The most thorough study of the relation of trees to ground water 

has been made by Cannon, who gives the following statement: 53

An extension of observations on tree distribution, as related to the depth of 

perennial water, to regions outside of southern Arizona, gives interesting, if 

not entirely conclusive, results. A comparison of the depth to ground water 

of the coastal plain of Texas as given by Taylor 54 with the distribution as 

given by Bray,88 for example, offers important suggestions in the present connection. In general it may be said that the stream bottoms of the coastal 

plain support a hardwood forest, which also extends over such upland as has 

a fairly shallowly placed water table. Such of the deciduous trees as are 

marked xerophytes for example, the post oak occur on dry ridges where 

pines of various sorts are also to be found and where the depth to permanent 

water is considerable. Of these trees, the root habit of the long-leaf pine is 

known. This species has a long taproot which penetrates to a great depth 

and which renders the species in a measure independent of surface conditions 

of soil and moisture. In the more arid southern portions of the coastal plain, 

where the water table lies below 50 feet, chaparral is characteristic of the 

upland, and along the streams, where the water table is less deep, forests occur.

Northward from Texas, as well as westward from the coastal plain of the 

State, are to be found conditions analogous to much already noted for southern 

Arizona and the coastal plain. That is, other things being equal, trees and 

forests, especially deciduous forests, are limited to areas where the depth to 

the water table is not great. Thus in Kansas and Nebraska the deciduous 

forests are mostly confined to the flood plains of streams, while the adjacent 

upland is treeless.

As one examines other regions (reference is made more in particular to those 

that are semiarid) he finds forests confined to such areas as are underlain by 

ground water not beyond the attainment by the roots of trees.

51 Sudworth, G. B., op. cit., pp. 144, 147.

52 Douglass, A. E., personal communication.

63 Cannon, W. A., Science, new ser., vol. 37, pp. 422-423, 1923.

54 Taylor, T. U., Underground waters of the Coastal Plain of Texas: TJ. S. Geol. Survey 

Water-Supply Paper 190, 1907.

85 Bray, W. L., Forest resources of Texas: U. S. Dept. Agr. Forest Service Bull. 47, 

1904. ~
PLANTS AS INDICATORS OP GROUND WATER 65

PROMINENT DESERT PLANTS THAT DO NOT HABITUALLY FEED ON GROUND WATER

The significance of the ground-water plants will be better understood and appreciated if attention is called to a few of the prominent desert plants that do not indicate ground water and do not 

habitually depend on the zone of saturation for their water supply.

The common sagebrush (Artemisia tridentata) is not an indicator 

of shallow ground water. It does not generally utilize water from 

the zone of saturation. It grows best in rather light soil, relatively free from alkali and with good drainage but with a fairly 

abundant supply of water, derived usually from rain or snow or 

from sheet floods and only exceptionally from the zone of saturation. In the Mud Lake Basin, Idaho, where the water table has 

been gradually rising during the last 25 years, presumably on 

account of irrigation in an adjacent area, the sagebrush has been 

killed by the ground water wherever the water table has risen 

near the surface. In these newly developed shallow-water tracts 

the ground-water plants have not yet gained much of a foothold, 

but a shallow water table is everywhere indicated by the presence 

of dead sagebrush. In Pahsimeroi Valley, Idaho, sagebrush was 

found growing to an unusual extent in association with greasewood and rabbit brush. The explanation of this association apparently lies in the fact that the subsoil of this valley is exceptionally gravelly and that therefore the fringe of capillary water 

above the water table is unusually shallow, thus leaving an aerated 

zone adequate for the sagebrush even in places where the water 

table comes within 5 feet of the surface and hence is within easy 

reach of the greasewood and rabbit brush. Doubtless sagebrush 

utilizes some ground water in this shallow-water tract, but its 

independence of the water table is shown by the fact that it forms 

the dominant vegetation over large areas in the valley where the 

ground water is certainly not within its reach.

Shadscale (Atripleas confertifoUa) is the dominant plant over very 

extensive desert areas in Nevada and Utah. It apparently occupies 

the upland areas where the conditions of soil and water supply are 

too unfavorable for sagebrush. It will grow in tighter soil than 

sagebrush, in places where its roots are restricted to the top soil by 

an alkaline subsoil, and in places where the precipitation is scanty 

and the soil is not wetted by floods. As a rule it does not thrive in 

soil that is wet on account of the capillary rise of ground water, and 

its presence is usually an indication that at least the surface foot is dry 

during the greater part of the summer. Although it mingles with 

ground-water plants such as greasewood, it.does not generally feed
66 PLANTS AS INDICATORS OF GROUND WATER

on ground water, and its greatest development is on the desert uplands where the water table is far beyond the reach of its roots. 

Over large parts of Nevada the little greasewood (Sarcobatm 

baileyii) , also an abundant member of the group that do not depend 

on ground water, is associated with the shadscale.

Farther south, in the vast deserts .of southern Nevada and of 

California, Arizona, and New Mexico, the familiar- vivid-green 

creosote bush (Covittea tridentata) is dominant over the very arid 

and stony uplands, where the water table if present at all is far 

beyond the reach of its roots. Bur sage (Frans&ria dwnosa) is 

associated with creosote bush in the extreme desert region of southeastern California and southwestern Arizona. Coleogyne (Goleogyne 

ramasisswia) grows in similar habitats but extends farther north, 

into Nevada and Utah.

Among the other truly desert types of plants found in the Southwest are the giant cactus, barrel cactus, cholla, prickly pear, and 

many other kinds of cactus, and the Spanish bayonet, Joshua treet 

ocotilla, and other kinds of yucca. All these depend on the moisture from the scanty rainfall, supplemented very rarely by .moisture 

from an occasional flood. They have no relation to the water table 

and do not habitually utilize ground water.

Some of the desert trees of southwestern Arizona and adjacent 

regions, notably the palo verde and ironwood, commonly grow on 

land that is high above the water table and so far as known have no 

tendencies to utilize ground water. They do, however, attain their 

best growth in the dry washes where the soil is occasionally wetted 

by flood waters. Brown 56 furnishes the information that ironwood 

forms a thin but persistent forest over large areas in the Salton 

Basin and Chuckwalla Valley, Calif., and is also present in nearly 

all the dry washes; and that palo verde is confined largely to dry 

washes in the desert. He states that both of these trees grow to 

heights of 15 or 20 feet in favorable localities, and that one palo 

verde tree 50 feet high was seen. These large and substantial trees 

are the marvel of the Southwest, for they grow where the rainfall is 

very meager and they are not ground-water plants.

Although ironwood and palo verde are especially partial to draws 

where they receive some natural irrigation, it is true that sagebrush, 

shadscale, creosote bush, yucca, and in fact most of the prominent 

plants that have been mentioned above as not dependent on ground 

water have their most luxuriant growth, though perhaps an abnormal 

and unwholesome growth, where they receive flood water in addition 

to the direct rainfall. None of them are known to show affinity for 

the water table, although under certain conditions any of them may 

doubtless utilize water from the. zone of saturation.

« Brown, J. S., op. cit., p. 18.
PLANTS AS INDICATORS OF GROUND WATER 67

RELATION OF PLANTS THAT FEED ON GROUND WATER 

TO OTHER GROUPS

RELATION TO PLANTS THAT LIVE IN WATER

Water-loving plants might be divided into those which grow 

entirely under water, those which have their roots only under water, 

those which have their roots in saturated soil, and those which grow 

where there is a zone of aerated soil between the land surface and 

the water table but where the water of the zone of saturation or of 

the overlying capillary fringe is within reach of their roots. The 

plants discussed in this paper consist of the last two of these groups. 

If the term hydrophyte were used in a very inclusive sense to comprise all four groups, then the ground-water plants would, of course, 

become a subdivision of the hydrophytes. A superficially logical 

distinction might be made between hydrophytes and ground-water 

plants if the former were regarded as plants that grow in surface 

water (groups 1 and 2) and the latter as plants that grow on land 

where ground water is available (groups 3 and 4). According to 

this distinction the rushes, sedges, and cat-tails are on the border 

line, being hydrophytes where they grow at the edges of pools and 

streams and ground-water plants where they grow on land.

However, the distinction as to whether the body of water that 

feeds the plant is surface water or ground water is perhaps less 

important than the relatibn of the roots to the body of water a 

question on which there is still great lack of information. Many 

ground-water plants probably develop a root system in the capillary 

fringe and avoid, so far as possible, sending their roots into the zone 

of saturation, thus differing in an important respect from true 

hydrophytes, whose roots are normally under water. However, the 

ground-water plants which are closely allied to the hydrophytes and 

which grow where the water table is very near the surface doubtless 

have functional roots in the zone of saturation. Moreover, G. E. P. 

Smith found both cottonwood and mesquite roots highly developed 

below the water table, and W. N. White found the roots of alfalfa 

extending somewhat below the water table.

The water table everywhere fluctuates. In most places within the 

areas occupied by ground-water plants the seasonal fluctuation 

amounts to 2 or 3 feet and in some places it is as much as 25 to 50 

feet. This fluctuation is probably beneficial because on the whole 

it produces a thicker belt of aerated soil that is moistened by ground 

water, but it raises interesting and important questions as to how 

the root system is adjusted to the fluctuations of the water table.

An example of the problem is afforded by the well of the late 

F. J. Jones, near Millett, Nev., which was measured monthly by him 

for the Geological Survey during a period of more than three years.
68 PLANTS AS INDICATORS OF GROUND WATER

In this well the water table- fluctuated between a low stage of 10.9 

feet and a high stage of 7.3 feet below the surface, the annual fluctuation being 2.5 feet in 1914, 3.5 feet in 1915, and 3.6 feet in 1916. The 

capillary fringe is about twice the thickness of this belt of fluctuation, but it is altogether probable that in the summer, when the 

water level is low, the salt grass and rabbit brush, which grow in 

the vicinity of the well, send feeders into the lower and wetter portion of the capillary fringe, close to the water table. By spring, 

however, this lower portion is submerged, and the plants must either 

draw their water supply from the zone below the water table or 

from another set of roots at a higher level or from both sources.57

An example of the problem where the fluctuation is unusually 

great is afforded by Pahsimeroi Valley, Idaho, in which seasonal 

fluctuations of more than 10 feet are common. The water table is 

usually lowest early in the spring, rises rapidly later in the spring, 

reaches its highest levels between June and September, and then 

subsides slowly but persistently until the next spring. Thus, most 

of the fluctuation occurs during the growing season. In the well of 

Dr. C. J. Gilman, in this valley, a total fluctuation of 38 feet has 

been recorded, the water level ranging from 2 to 40 feet below the 

surface.58 In low stages of the water table the greasewood and 

rabbit brush in the vicinity of this well have an unusual range of 

moist aerated soil in which to develop their roots, but in the high 

stages this root system becomes submerged.

In salt-grass areas in which there is a great fluctuation in the water 

table the salt grass may be dormant during the low stages. This 

condition prevails in places around Great Salt Lake, where the low 

stage occurs in the fall.59

RELATION TO SALT-RESISTANT PLANTS

The salt-resistant plants, or halophytes, in the arid regions virtually form a subdivision of the ground-water plants, because the 

alkaline soils in which they grow are almost wholly confined to 

the areas that have ground-water discharge. Nevertheless, these 

plants, or at least the succulent species, such as pickle weed and samphire, which are found in the most alkaline soils, resemble the droughtresistant plants, or xerophytes, in that they have to subsist on very 

small quantities of water. The economy in the use of water may be 

required even of plants that grow in saturated soils. The explanation of this paradoxical condition is found in the well-known fact 

that a plant in order to absorb soil water must have a tissue fluid

B7 Meinzer, O. E., op. cit. (Water-Supply Paper 423), pp. 100-102. 

88 Idaho Bur. Mines and Geology Pamphlet 9, pp. 24, 25, 1923. 

^Aldous, A. E., personal communication.
RELATION" TO OTHER GROUPS 69

of higher osmotic pressure and therefore of higher salt content than 

the soil water. For this reason the highly concentrated soil water 

is relatively unavailable to the plants, and the soil that contains such 

highly concentrated water is said to be physiologically dry even if 

it is saturated. Because of the slow rate at which these salt-resistant 

plants absorb water, they require adaptations for controlling 

transpiration similar to those of the drought-resistant plants. The 

high concentration of the tissue fluid itself retards transpiration.

The soils and subsoils underlying many of the play as and adjacent belts of succulent salt-resistant plants are, moreover, very 

clayey and tight and therefore have only small supplies of available 

water, in spite of the high water table and abundant water supply 

of the surrounding belt of more permeable soil. Thus the supply 

available to plants may be meager because of the fine texture and 

impermeability of the soil and subsoil as well as the high concentration of the soil water. It has been shown that the clay cores 

underlying many of the play as are virtually impermeable and have 

only very sluggish capillary movement of water. Thus their 

barrenness is due, at least in large part, to their deficiency of an 

available water supply.

It is known, however, that in the more permeable belts surrounding the clay cores a very alkaline soil may be underlain by ground 

water that is not excessively mineralized and that may indeed be 

very pure. Grasses that flourish on alkaline soil, such as salt 

grass and alkali sacaton, apparently have considerable transpiration. This fact leads to the suggestion that they may obtain most 

of their water supply not from the physiologically dry soil but 

from the relatively pure water of the zone of saturation. The 

leaves of tamarix are known to have glands for excreting salt,60 

and the leaves of salt grass apparently have a similar adaptation. 

This may enable the salt grass to function as a true salt-resistant 

plant at times when only highly concentrated soil water is available 

but to reduce its sap concentration and to transpire more freely 

when there is an adequate supply of better water. Deep-rooting 

plants that are found in alkaline soils may also be relatively independent of the alkali in the top soil and may feed on the relatively 

pure ground water. The young plants of such species must, however, have the ability to endure the alkaline soil until they are able 

to send their roots to the required depth, and this property is known 

to be possessed by the seedlings of greasewood.61

60 Coulter, J. M., Barnes, C. R., and Cowles, H. C., A textbook of botany for colleges and 

universities, vol. 2, Ecology, p. 621, New York, 1911. 

6l Kearney, T. H., op. cit., p. 405.
70 PLANTS AS INDICATORS OP GROUND WATER

The recent work of Harris 62 and others on sap concentration bears 

on this subject. Work of this kind could be applied more directly 

to the questions of the relation of the salt-resistant plants to the 

water in the zone of saturation and the significance of these plants 

as indicators of quantity and quality of ground water. The investigations of the native plants in Tooele Valley by Harris and his 

colleagues showed that the concentration of sap in greasewood, salt 

grass, and alkali sacaton was low as compared with that in pickleweed, samphire, and shadscale; furthermore, that the minimum concentration in greasewood, salt grass, and alkali sacaton was only 

moderately in excess of the concentration in sagebrush and dryfarm grains. These relations are shown by the following summary 

table:

Chloride concentration in the tissw fluids of native plants in Tooele Valley,

Utah

[As shown by work of J. A. Harris and others]

Plant associations and species

Sagebrush association of alluvial fans: 

Artemisia tridentata ° _ - _ _-

Greasewood-shadscale association:

Atriplex confertifolia.-. . . . __

Allenrolfea occidentalis... ,__ _ ... __ _ __ ......

Grass-flat communities: 

Allenrolfea occidentalis.. .... __ ... _ _ _.

Sporobolus airoides ____ ..... _ . .. _ --------

Salt-flat communities:

Number 

of tests

4

7 

6 

5

5 

3 

3

4 

8

Chlorides (grams per liter)

Minimum

2.1

4.8 

19.5 

14.9

14.6 

7.0 

7.9

14.7 

25.5

Maximum

3.6

14.3 

64.4 

23.5

25.0 

15.2 

20.0

26.1 

37.1

Average

2.7

8.7 

39.8 

17.5

19.6 

11.4 

13.8

22.9 

30.0

0 The concentrations in sagebrush (Artemisia tridentata) are of the same order as those found near the 

end of the season in small grains as grown under dry-farm agriculture at Nephi, Utah.

RELATION TO DROUGHT-RESISTANT PLANTS

The desert ground-water plants may have a humid environment 

for their roots, but they resemble the drought-resistant plants, or 

xerophytes, in having a dry environment for their transpiratory organs. Moreover, some ground-water plants, chiefly those which 

send their roots to great depths to reach the water table, have considerable ability to endure adverse soil-moisture conditions when they 

are not in contact with an adequate ground-water supply. The 

young plants of these species, if they have grown from seeds, must 

be able to withstand drought until their roots reach the ground 

water; moreover, if they find ground water only at great depth the 

rate at which they can lift the water to their stems and leaves may be 

too slow to allow rapid transpiration.

63 Harris, J. A., and others, The osmotic concentration, specific electrical conductivity, 

and chlorid content of the tissue fluids of the indicator plants of Tooele Valley, Utah; 

Jour. Agr. Research, vol. 27, pp. 893-924, 1924. See also the bibliography in this paper.
RELATION TO OTHER GROUPS 71

Seeds of deep-rooting plants may, of course, germinate wherever 

they happen to be dropped, and the young plants will live and grow 

as long as they can, regardless of whether the water table is 15, 50, 

or 200 feet below the surface. Thus some plants may send roots 

to great depths and yet fail to find ground water because the water 

table is still lower. These plants will obviously not give up the 

struggle for existence because they do not find ground water; they 

will struggle on as long as they can, even under adverse conditions. 

Evidently, therefore, these deep-rooting plants tend to break away 

from the strict control of the water table and to spread to areas where 

they do not draw on the ground-water supply. There is evidence 

that the deep roots are not sent downward through dry soil but 

make their deep growth when or where they can do so in moist soil. 

Nevertheless the water supply of such species must be precarious 

over large areas except as ground water is reached, and hence these 

species have need for adaptations to resist drought until they have 

tapped the ground-water supply.

However, the individuals that reach the water table are likely to 

survive and to reproduce their kind in preference to those that are 

less successful in developing deep roots. Moreover, as a rule, among 

the individuals that reach the water table those will reproduce most 

which are the most capable in utilizing the ground water. Hence, 

natural selection should produce a species which can exist drought 

but which nevertheless has great capacity to send strong roots to 

great depths rapidly and to pump ground water effectively up 

through these roots.

It was found by W. N. White,63 in his work in Escalante Valley, 

Utah, that the small plants of greasewood which he dug up to transplant into soil tanks were all connected by roots or runners with 

larger and older greasewood plants. This would seem to be the most 

effective means of propagation by deep-rooting ground-water plants.

RELATION TO NORMAL PLANTS OE HUMID REGIONS

A number of species that are widely distributed through, the humid 

regions also grow as ground-water plants in arid regions. These 

plants are chiefly forest trees, such as birch and sycamore. They 

are generally regarded as mesophytes rather than as hydrophytes. 

They are mesophytes in the sense that they can not tolerate much 

alkali and apparently have no special adaptations .for resisting 

drought. In the arid regions they are found in the mountain canyons and large arroyos that have an underflow and in other places 

that have shallow ground water but fairly good drainage. They are 

commonly not associated with salt grass and greasewood on the

68 Personal communication.
72 PLANTS AS INDICATORS OF GROUND WATER

alkaline soils, nor with mesquite in areas of good soil where the water 

table is at considerable depth.

Even casual observation of the forests in humid regions will show 

that the trees of this type have an affinity for the water table in such 

regions as well as in arid regions. It is this affinity that enables 

trees such as birch and sycamore, which are recognized as especially 

water-loving genera in humid regions, to flourish in areas of ground 

water in'arid regions; and it is the lack of this property in many 

other forest trees of smaller water requirement in the humid regions 

that accounts for their absence from such ground-water areas in arid 

regions. If it were not for the ability of the trees of the waterloving group to utilize water from the zone of saturation and the 

poor development of this ability in other trees it could reasonably be 

expected that the other trees would be the most successful and the 

water-loving trees the least successful in establishing themselves in 

the arid regions.

The distribution of the native vegetation throughout the eastern 

part of the United States is influenced by the water table to a much 

greater extent than is realized by most persons who have not given 

much attention to the occurrence of ground water. In some places 

in the woodlands near Washington, D. C., ferns have been observed 

adhering about as closely to tracts of shallow ground water as the 

well-recognized ground-water plants in the West, and many similar 

examples of the relation of plants of a particular species to the water 

table can readily be found almost anywhere in the East.

VALUE OF PLANTS AS INDICATORS OF GROUNDWATER CONDITIONS

OCCURRENCE OF GROUND WATER

The plants described in this paper are without question of great 

practical value as indicators of the occurrence of ground water in 

arid regions. They give evidence which supplements that furnished 

by the topography and geology and which is more specific as to the 

precise localities where the water occurs near the surface. They can 

not properly be ignored or relegated to casual consideration in 

any ground-water survey of a desert region. Many inhabitants of 

desert regions have a keen appreciation of the value of plants as 

indicators of ground water and an almost intuitive sense of the 

significance of particular native species. Doubtless some of this 

practical knowledge was possessed by primitive man long before 

the dawn of human history, and indeed as long ago as men first 

essayed to dwell in the deserts or to cross the vast expanses of these 

dread regions.
VALUE OF PLANTS AS INDICATOKS 73

The value of a plant species as an indicator of ground water 

depends chiefly on the extent to which it is absent from areas where 

it can not feed on ground water. No species can be relied upon as 

an infallible indicator, for even the most consistent ground-water 

plants will grow in some areas where ground water is not available 

but under conditions that closely resemble those in the areas of shallow ground water. However, in the desert regions water supplies 

are so scarce that these simulating conditions can usually be detected 

without much difficulty. Much uncertainty may, however, exist as 

to the interpretation in particular localities of species that feed 

on ground water wherever they have an opportunity and yet have 

enough capacity to resist drought to succeed in maintaining themselves in relatively moist places far above the water table. For this 

reason more information is needed as to the distribution of the leading ground-water species and the extent to which they grow outside 

of the areas of shallow ground water. It is important to know how 

the different species rank in regard to the ground-water habit, and, 

so far as possible, to base forecasts concerning the occurrence of 

ground water on the most reliable species only. Obviously, however, 

this rule can not always be applied, for in some localities only species 

of doubtful significance are found.

In addition to their value as indicators of localities where water 

supplies may be developed by digging or drilling, the ground-water 

plants are of great value to travelers in the desert in directing them 

to existing watering places. How valuable they are in this respect 

can hardly be appreciated by anyone who has not traveled in such 

regions, and on the other hand, the habitual desert traveler uses 

the clues they afford without considering the service they render him. 

In an uninhabited region in which the distances between watering 

places may be 10, 20, or 50 miles it is sometimes difficult for a 

stranger to locate the precise spot where water occurs. It may be 

difficult even with detailed maps and directions such as are given in 

the desert guidebooks that have been published by the Geological 

Survey; it is likely to be still more difficult when only indefinite, 

hearsay directions are available. Eoads and animal trails generally 

converge toward watering places, and signposts may be found that 

indicate the direction to water. At many watering places, however, 

the vegetation helps greatly in finding the water. The most valuable 

type of vegetation, of course, consists of trees, such as clumps of 

cottonwoods or of tall, stately palms, which may be visible from a 

great distance, but much help and comfort may also be afforded by 

so humble a ground-water indicator as salt grass, either by being 

visible at a distance as a green patch, or by giving at closer range 

definite assurance of the proximity of ground water and a virtual 

indication that the watering place is not far away.
74 PLANTS AS INDICATORS OF GROUND WATER 

DEPTH TO THE WATER TABLE

As has already been shown, the ground-water plants indicate not 

only the occurrence of ground water but also to some extent the 

depth to ground water; that is, the different species have different 

general limits of depths. Some species will grow where the water 

table is virtually at the surface but have maximum limits of depth 

to the water table beyond which they do not grow or at least do not 

grow luxuriantly, others have both minimum and maximum limits 

of luxuriant growth. With a few exceptions, the greatest depth 

from which ground water is known to be lifted by plants is about 

50 feet.

The limits of depth for all species are somewhat indefinite, and 

the lower limits are more indefinite than the upper. The depth 

to which the roots of a given species will penetrate is affected by the 

texture of the soil. In general the maximum limit is deeper for 

loose, easily penetrated soil than for tight soil that is difficult to 

penetrate. Hardpan near the surface and impervious materials at 

the depth where the water table would normally occur, of course, 

disturb the relations greatly. For some species the minimum limit 

is less in coarse soil that has a thin capillary fringe than in soil of 

finer texture that has a thick fringe.

The clues that can be obtained from the different ground-water 

plants as to the approximate depth to water are of considerable 

practical value. For persons in distress they may be a matter of 

life or death. Thus a person without tools and in a weakened condition might be unable to dig down to the water that supplies a 

mesquite, although he would have a good chance of finding water 

where salt grass and palm trees are growing. Also, in estimating 

for a given area the acreage of irrigable land within certain feasible 

limits of lift, excellent use can be made of the clues furnished by the 

successive belts of ground-water plants.

In the investigations of Sulphur Spring Valley, Ariz., the Tularosa 

Basin, N. Mex., and Big Smoky Valley, Nev., the writer selected 

specific localities for intensive study bearing especially on the problem of irrigability with ground-water supplies. In these localities 

samples of soil were usually taken for determination of the alkali 

content, the depths to the water table were determined or estimated, 

the dominant species of native vegetation were observed, samples of 

water were usually taken for analysis, and various other observations were made. In the discussion of the principal ground-water 

plants on pages 16-64 much use has been made of the specific data 

obtained from these locality studies. Below are given most of the 

base data on the relation of the leading plants of this class to the 

water table.
VALUE OF PLANTS AS INDICATOES 75

Relation of ground-water plants to depth of water table below surface at specific

localities

Sulphur Spring Valley, Ariz.

' Locality

1. __________ - - 

2.................... .... ... -

3.... ... ... ... ... 

4 __ . __ . _ . ______ -

5_ 

6. __ . __ -..-_ - - -

7 

8....... 

g

10 ...... 11-... . -

12............ _ . __ . _ 1?

14........ ....................

15. 

16. _____ . _ . __

n... ......... ... . ... ............

18 . 

19........ __ . __ 

20 

21.............. . _ . __ -

22. __ __ _

23 

24......... ___ ..... 

25 . _ 

26. 

27.. ......................

28 ______

29 

30 

31. ___ . _ . ___ 

32. ___ .... ___ ...... ..... 

33... .........................

34. _ . _ . __ ....... -

35 

36 ____ . _ .. _

37 

Of}

39. ____ . ___ ... __ . 

At\

41

<W

44..... ... ... 

45 

4fi

47 . 

48 ___ 

60.... 

51 

CO

54. ... 

55.. ________ _

56 

57 . 

58. 

59.. ... fin

61. _ .. __ . - - 

62 __ .... _ . __ .......... 

64

65 

Depth 

to water 

table 

(feet)

4

4

4

, 4

5

«5

6

«7

7

7

7

-8

»10

-10

10

10

10

10 »10

11

11

«11

11

12 »13

13

14

14 »14

»15

15

» 15

»15

16

»17

17

18 -18

»18

19

20

22

22

»24

24 »25

»25

-27

27

29 *M

30

»30

31

32 -35

 35

» 35

40

42

a 4.%

50

50

Seepweed 

(Dondia)

Mexican 

salt grass 

'Eragrostia 

oUuaiflora)

X

Alkali 

sacaton 

'Sporobolus 

airoides)

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

Cbamiso

(Atriplex 

canescenst)

X

X

X

X

X

Mesquite 

(Prosopis 

glandulosa)

X

X

X

X

X

X

X

X

X

X

X

X

X

X

 X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

"Estimated.

54386 27-
76 PLANTS AS INDICATORS OF GROUND WATER

Relation of grounds-water plants to depth of water table Continued

Tularosa Basin, N. Mex.

Locality

1 

2 

3 

4. ..........................

5. -

6. 

7. -

8. . ..... -

9

10. 

11. 

12 ..........................

13 

14. 

15 _ 

Ifi 

17. 

18. 

1Q

20 - _ - i - - - -

91

oo

oo 

24. 

25 

26 

O7

28..... .. 

29

Qn

Q-l

QO

00

Depth to 

water 

table 

(feet)

1

"2

2

"2

3

3

4

6

"8

"10

11

13 "15

"15

17

20

20

22 "23

"23

"25

-25

"25

"25

"25

"25

28

30

31

39

45 "60

62

Barren

X

X

X

Pickleweec 

(Allenrolfet 

occidentals .

X

X

X

X

X

X

X

X

Salt grass 

(Distichlis 

spicata)

X

Chamiso 

(Atriplex 

canescens"!)

X

X

Mesquite

X

Big Smoky Valley. Nev.

Locality

1 .. 

3 

5 

6 

8 -

9 

10 

11 

12 

13 

14.. ......... 

15 . 

16 . 

17 

18 

19

20 

22 . .

23 

24................

25 

26 ...........

27.. 

28..... ...........

29 

30... ...... .......

31 

32...... ..........

33 

Depth 

to water 

table 

(feet)

0

0

2

2

2

3

3

3

4

4

6

6

6

7

7

"8

9

9

10

10

"13

a 19.

14 "14

"17

"23

OQ

a o^

 33

"60

Barren

X

X

X

Pickleweec 

(Allenrolfea 

occidentalis

X

Salt 

grass 

(Distichli 

spicata)

X

X

X

X

X

X

X

X

X

fiabbit 

brush 

( Chrysothamnus 

graveolens)

X

X

X

X

X

Big 

greasewood 

(Sarcobatus vermiculatus)

V

V

X

X

X

X

X

X

X

X

X

X

X

X

X

Willow 

(Safe?)

X

Salt bush 

(Atriplex 

torreyi)

 Estimated.
VALUE OF PLANTS AS INDICATORS 77

The propriety of making concise generalizations of depths to the. 

water table indicated by the several species of ground-water plants 

may well be questioned iff view of the. inadequate data now available. 

However, in order to give a somewhat tangible basis for future work 

on this subject such generalizations are attempted in the following 

outline:

Rushes and sedges: Water at surface or water table within a few feet.

Giant reed grass (Phragmites communis) : Water at surface or water table 

within a few feet, probably as much as 8 feet.

Giant wild rye (Elymus condensatus) : From very near surface to 12 feet or 

more. In subhurnid regions giant wild rye may grow without relation to the 

water table.

Salt grass (DisticMis spicata) : From very near surface to a maximum of 

12 feet, or rarely more.

Mexican salt grass (Eragrostis obtusiflora) : From very near surface to about 

15 feet.

Pickleweed (Allenrolfea ocddentalis) : Water table generally within a few. 

feet, but this species may occur where the water table is as much as 20 feet or 

more below the surface.

Arrow weed (Plucked sericea) : Water at surface or water table at depths 

ranging to 10 feet or more, possibly as much as 25 feet.

Palm trees ( WasMngtonia filamentosa) : Water table within a few feet.

Willow: From surface to 12 feet or more below surface (?).

Alkali sacaton (Sporobolus airoides) : From less than 5 feet to 25 feet, and 

in some places much more. Most luxuriant growth where depth is between 5 

and 15 feet. Alkali sacaton that occurs where depth is much more than 25 feet 

probably does not send roots to ground water.

Rabbit brush (Ohrysothamm^s graveolons) : About 2 to 15 feet. More than 

about 8 feet for most luxuriant growth. This species also probably grows 

where it does not utilize ground water.

Big greasewood (Sarcobatus vermicultttus) : From 3 feet or less probably to 

40 feet or more. Abundant and luxuriant growth where water table is between 

10 feet (or less) and 20 feet. Greasewood that occurs where depth is more than 

40 or 50 feet probably does not send roots to ground water.

Mesquite (Prosopis) : From less than 10 feet to 50 feet or more. Mesquite 

that grows where depth is much more than 50 feet probably does not send roots 

to ground water.

QUALITY OF GROUND WATER

That certain plants indicate the quality as well as the occurrence 

of ground water is widely believed by people in arid regions, and 

there is doubtless some basis for this belief. However, the indications of quality are not so definite as those of occurrence and should 

be regarded merely as general probabilities.

In general, the rushes, sedges, and reeds indicate fairly good water, 

but there are probably many exceptions to this rule. The Rye 

Patch, in Ralston Valley, Nev., in which giant reed grass and wild 

rye are prominent, is underlain to a depth of 50 feet with water of 

excellent quality, but in lower Big Smoky Valley the reed grass 

grows where the water is probably more mineralized. The succu-
78 PLANTS AS INDICATORS OF GROUND WATER

lent alkali-resistant plants, such as pickle weed and samphire, are 

likely to indicate highly mineralized water immediately under the 

water table, but the water a little deeper may be much better. Where 

salt grass or alkali sacaton is growing the water may be good or it 

may be very bad. Palm trees and greasewood also indicate water 

of doubtful quality, but potable water can generally be obtained in 

the vicinity of healthy palms. Mesquite generally though not invariably indicates good water. Shrubs and trees that normally grow 

in humid regions, such as roses, birch, and sycamore, commonly indicate good water.

The principal data available on the relation of ground-water plantsto the mineral character of the ground water in three of the regions 

that were most carefully studied by the writer are given in the following tables. As a rule, the samples of water for which analytical 

data are given were obtained from dug or bored wells that extended 

only a few feet below the water table or from springs that dischargeshallow ground water. Thus, the data represent the upper layer of 

ground water that is, the ground water that occurs immediately 

below the water table, or at most not many feet below it. Obviously 

the water that occurs far enough below the water table to be beyond 

the reach of plant roots can not influence.the character of the vegetation and should therefore be eliminated from such a study.

Total solids and certain mineral constituents of water from springs and shallow 

wells where specified ground-water plants are growing

Sulphur Spring Valley, Ariz.

[Analytical results in parts per million]

Designation

I............

2............

3_ ........

4............

5 __ ........

6 __ ........

7............

8. ........

9.. ...... .

10............

11... ......

12 __ .........

33... .........

14............

15 __ .........

16...... ......

17.. ..........

18............

19............

20............

21 __ ........

22-..-.. ...

23. ........

Depth 

of well 

(feet)

(?)

25

(a\

W

25

33

C)

(a)

35 (?)

19

23

40

15

20

C)

20

.«47

(a\

C)

40

14

Depth 

to water 

level 

(feet)

49

11

&8

14

17

31

oo

1Q

10

24

10

20

35

7

11

22

17

6

6

7

qi

10

Total 

solids

1 OR

230

234

268

97ft

OSM

294

OQC

QAA

304

336

336

340 070

410

424

526

620

708

1,268

1 Q19

1 1XA

Sulphate 

radicle 

(S04)

7

iq

on

11

10

21

84

qq

60

qx

9Q

53

QQ

QQ

98

97Q

184

* 1,157

Chloride 

radicle 

(01)

10

10

7

19

on

91

10

10

7

16

7

20

36

47

41

63

47

48

80

53

19A

9 (Ml

Black 

alkali as 

NasCOs

0

A*>

QA

42

6

0

17

110

127

Af>

72

199

91

qc

203

136

QIC

qcjs

670

1,163

0

0

Ground-water plants

alkali sacaton.

]yj Ago iii t6

Do.

Do.

Do.

Do.

Do.

Do.

« Shallow dug well.

»10 feet where alkali sacaton was observed.

o Cased nearly to bottom. * E! A 

d Permanent hardness as CaSOi is 881.
VALUE OP PLANTS AS INDICATORS 79

Total solids and certain mineral constituents of water from springs and shallow 

wells where specified ground-water plants are growing Continued

Tularosa Basin, N. Mex.

Designation 

1610..........

1424... ___ ..

1106. ___ ....

1710... __ ..

1626..........

S26...........

1304..........

1407..........

S17... ........

1721... .......

Depth 

of 

well 

(feet)

17

35

85

65

60

(0 40

62

Depth 

to 

water 

level 

(feet)

12 /29

62

24

30

4

17

28

o i

Total 

solids

1,670

2,250

2,407

2,633

4,241

4,576

4,856

4,870

5,500

11,640

Sodium 

and 

potassium 

CNa+K)

1I5R

157

567

339

495

4"vi

442

526

748

1,482

Sulphate 

radicle 

(BOO

702

1,039

699

1,111

1,250

2,100

2,370

2,590

2,367

3,786

Chloride 

radicle 

(Cl)

94J.

93Q

700

288

1 ft79

576

616

523

1,130

Ground-water plants

Do.

 The designations are those used in Water-Supply Paper 343.

/ Estimated 45 feet at short distance from well where vegetation was observed.

* Extends short distance below water table.

Big Smoky Valley, Nev.

Designation *

Sll-.......-

W8---..- 

W 10... ......

"W 14.. .......

"W6- ......

"W 18--.-.-.-.

W17.........

W2... .......

'W I. ........

~W 20.- ......

"W 4 .._..__

S8 ........

S 15.. ........

£>7... ........

W9 ____ ...

W22.. ......

W 19... ......

W 21. ........

Depth 

of well 

(feet)

10

12

14

15

50

63

22

15

3

5

16

19

6

4

Depth 

to water 

level 

(feet)

< )

7

6

4

9

>37

'38

17

12

3

2

5

10

2

Total 

solids

180

OOA

313

390

363

4QA

764

2,405

369, 985

137

267

353

439

KftQ

RfiQ

4,038

Sodium 

and 

potassium 

(Na+K)

6

33

31

6

55

114

70

98

765

143, 616

38

7

70

190

1,218

Sulphate 

radicle 

(800

13

31

01

69

48

50

Q3

90

781

18, 624

16

53

62

58

7Q

169

917

Chloride 

radicle 

(Cl)

4

10

0£

18

11

21

74

68

171

501

168, 812

91

19

66

en

1,361

Ground-water plants

Do.

Salt grass, tules, roses, Lombardy poplars, and boxelders.

Do.

Salt grass, rabbit brush, greasewood. 

Do.

wood, roses, buflaloberry 

bushes. -

wood Atri-plex torreyi.

Ralston Valley, Nev.

W 30... ...... 50± 5 273 38 16

rye, salt grass, rabbit brush, 

greasewood.

. Clayton Valley, Nev.

W26 ____ .. 28 23 3,611 QQ7 997 1,665

* The designations are those used in Water-Supply Paper 423.

«' Water table very near surface.

i Estimated 33 feet at short distance from well where vegetation was observed.

* Observed y% mile west of spring.
80 PLANTS AS INDICATORS OF GROUND WATER

Range of total solids, chloride radicle, and "black alkali in ground water at 

points where specified ground-water plants are growing

Sulphur Spring Valley, Ariz.

Plant

Number 

of 

analyses

8 

16 

12 

2

Substances dissolved in ground water, 

in parts per million

Total solids

230-1, 912 

230-7, 154 

186-2, 008 

340-7, 154

Chloride 

radicle 

(Cl)

7-80 

7-2,941 

7-784

20-2, 941

Black 

alkali as

NasCOj

42-1, 153 

0-1,153 

0-318 0-21

Tularosa Basin, N. Mex.

4

7

6

1,670-5,600

l,670-°4,856

244-1, 130

239-«616

239-2, 841

Big Smoky Valley, Nev.

13

9

10

4,038

137H1, 038

137-2,405

117 9 df}^

1,361

4-1, 361

4-501

4-501

« Exclusive of sample from well 1721, which came from a considerable depth below the water table.

The data in the foregoing tables show that all the species listed, 

with the possible exception of pickleweed (Allenrolfea occidentdlis), 

may grow where the upper layer of ground water contains only small 

amounts of mineral matter and is of good quality. Thus, of 13 

samples of ground water obtained in Big Smoky and Ralston Valleys at points where salt grass was growing, 11 contained less than 

1,000 parts per million of total solids, 8 contained less than 500 parts, 

and 5 contained less than 300 parts, the minimum being only 137 

parts. Of these same 13 samples morp than half contained less than 

35 parts per million of chloride, the minimum being only 4 parts. 

Likewise, of 8 samples in Sulphur Spring Valley at points where 

Mexican salt grass was growing, 5 contained less that 500 parts of 

total solids and 6 contained less than 50 parts of chloride. Greasewood and rabbit brush, in Big Smoky Valley, and alkali sacaton and 

inesquite, in Sulphur Spring Valley, have equally good records. 

For example, out of 10 samples of water taken where greasewood 

was growing, 7 contained less than 500 parts of total solids and 6 

contained less than 35 parts of chloride. The record for pickleweed 

is not so good, though the number of samples is too small to be conclusive, especially as all except one came from Tularosa Basin, where 

most waters are highly mineralized. The best of these waters contains 1,670 parts of total solids and 244 parts of chloride a poor 

water, but one that can be used for drinking if necessary.
VALUE OP PLANTS AS INDICATOES 81

On the other hand, the data show that all these species may be 

found growing where the ground water is highly mineralized, even 

mesquite not being an exception. This is not surprising in view of 

the usual high concentration of soil moisture in comparison to that 

of ground water. The alkali in the soil where the species under consideration are growing is shown in the following table. To make 

clear the significance of the data in this table it should be stated 

that if a soil with a specific gravity of 1.6, a porosity of 40 per cent, 

and an alkali content of 1 per cent is saturated and all of the alkali 

passes into solution, the soil moisture will contain about 40,000 parts 

per million of total dissolved solids, which is about five times the 

concentration that cattle can endure and about ten times the concentration that human beings can endure. If the alkali is not all in 

solution the concentration may be^ less, whereas if the soil is not 

saturated the concentration may be even greater. It is evident from 

the table that the plants under consideration must be able to tolerate 

water with much larger amounts of mineral matter than man or 

other animals can tolerate, for instead of using the ground water in 

its unmodified condition they must to a large extent use the soil 

moisture, which is essentially a concentration product of the underlying water. Even though the ground-water plants may to some 

extent avoid the soil alkali by getting their feeding roots close to 

the water table they can not wholly avoid it, especially at times 

when a part of the alkali is washed down to the water table. For 

this reason it is perhaps futile to expect that any definite relations 

can be found between the occurrence of ground-water plants and the 

quality of the ground water or that any species of such plants that 

can grow in even moderately alkaline soil will invariably indicate 

potable water.

AlJcali in soils analysed in which specified ground-water plants are growmg

[In percentage of total dry soil by weight. Depth to which the soil was sampled ranged from 1 to 6 feet

and was generally 4, 5, or 6 feet]

Pickleweed:

Seepweed: 

Sulphur Spring Valley. . 

Salt grass:

Mexican salt grass: 

Sulphur Spring Valley. . 

Alkali sacaton: 

Sulphur Spring Valley.. 

Qreasewood:

Chamiso:

Mesquite: 

Sulphur Spring Valley- - 

Tularosa Basin _ ... ...

Number of analyses

10 

2

4 

8 

17 

11 

19

11 

12

Total soluble solids

Minimum

1.75 

.86 

.79 

.33 

.21 

.81 

1.20

.14 

1.10

Maximum

4.20 

1.27 

1.32 

1.24 

1.93 

2.19 

2.80

1.93 

2.25

Average

1.06 

1.06 

.79 

.82 

1.39

.62

Sodium chloride

(NaCl)

Minimum

0.40

Trace.

Trace.

Maximum

1.55

.90

.60

Average

.......

Black alkali

(NajCOs)

Minimum

0.14

.01 

0

0

Maximum

0.34

.58 

.48

.48

Average

0.24

.28 

.19

.11
82 PLANTS AS USTDICATOES Ol)1 GEOTJFD WATEE 

QUANTITY OF GROUND WATER

Relation of transpiration of ground\-water plants to water-supply 

projects. In many of the arid valleys of the West projects for 

pumping large quantities of water from wells for irrigation or 

public supplies have been carried out or are under consideration. 

3Tor these projects it is necessary to know as nearly as possible how 

much ground water can be recovered year after year without seriously depleting the supply stored in the underground reservoirs. As 

a rule the pumpage should not exceed the natural discharge, but 

should merely salvage the ground water that would otherwise be 

disposed of by natural processes. In these valleys the ground water 

is naturally discharged largely by transpiration from the vegetation, 

and hence information as to the amount of transpiration bears 

directly on the very important practical question of the supplies 

available for economic uses such as those of irrigation and city 

water works.

Analysis of the problem of quantity of water transpired. To 

estimate the quantity of ground water that is annually discharged 

by the plants of a given valley it is necessary to determine the areas 

.occupied by these plants and the rate at which they discharge water 

by transpiration. The rate of transpiration is generally expressed 

in inches or feet of depth of a layer of water covering the entire 

area and is comparable to the rainfall and the evaporation from a free 

water surface as usually expressed. If the area occupied by a 

 certain association of ground-water plants is expressed in acres and 

the rate of transpiration from them in feet a year, the product of 

these two quantities represents the total annual discharge by transpiration from this association in acr^-feet.

The area factor. The areas occupied in a given valley by the 

different associations of ground-water plants can readily be determined by a survey of the valley. T^ie information thus obtained, 

even without any definite data as td the rate of transpiration, is 

of great practical value in estimating the probable safe yield of 

the valley and in determining the magnitude of pumping projects 

to be undertaken. For example, in Steptoe Valley, Nev., in which 

exploratory drilling was done several years ago by the United 

States Geological Survey,64 it was found that ground water is being 

discharged, through evaporation from soil or through the growth 

of native plants such as salt grass, rabbit brush, and greasewood, 

over an area of about 115,000 acres. (See fig. 10.) In most places 

the plants mentioned have a good stand and a luxuriant growth, 

indicating that they enjoy an ample water supply. The discharge 

per acre is probably much less than the quantity of water required

64 Clark, W. O., and Rlddell, C. W., op. cit. (Wajter-Supply Paper 467), p. 13.
VALUE OF PLANTS AS INDICATOES 83

per acre to irrigate ,useful crops, such as alfalfa, grain, or vegetables, and, moreover, not all of this water can be salvaged by 

pumping from wells. Nevertheless, the great extent of the area of 

discharge and the luxuriant character of its vegetation give reliable 

evidence that a substantial supply of ground water is available.

The value of information of this kind for furnishing reliable 

clues as to the presence or absence of a substantial supply of 

ground water in a given valley was impressed upon the writer 

in 1917, when he made a reconnaissance of Steptoe Valley and 

several other relatively well-watered valleys of east-central Nevada 

and then proceeded immediately to southeastern California for a 

reconnaissance of a number of most arid valleys of the Mohave 

Desert and Salton Sea regions. The difference was truly impressive. In the Nevada valleys he rode for miles through areas of 

discharge with moist soil and luxuriant ground-water plants; in 

the desert valleys of California, on the other hand, he found either 

no areas of ground-water discharge or else surprisingly small areas 

covered with a meager ground-water vegetation that showed the 

stress of unfavorable conditions.

The rate factor. Although a survey of the areas of discharge of 

a certain valley gives information on which rough estimates of its 

ground-water supply can be based, much more accurate estimate!? 

can be made if data are also obtained on the rate of discharge. 

Until recently very little work was done on the rate of discharge 

by ground-water plants. A large amount of work has, indeedr 

been done by botanists on transpiration and by students of agriculture on the water requirements of useful plants, but the great volume 

of data that has accumulated from these investigations is not directly 

applicable to the hydrologist's problem of ground-water discharge. 

However, good use can doubtless be made of some of the methods 

of investigation already developed for these other purposes and,, 

moreover, much of the large mass of data that has been obtained 

can be interpreted and applied to the ground-water plants.

In 1910 and 1911 a very valuable investigation was made by 

Charles H. Lee 65 of the rate of discharge from land covered with 

salt grass in Owens Talley, Calif. The salt grass was grown in a. 

series of tanks filled with soil in which the water table was held at 

different depths below the surface. The records showed the total 

discharge of ground water, including both transpiration from the 

salt grass and evaporation from the soil to which the water rose by 

capillarity. Because of the lack of other data the results obtained in 

this investigation have been used in making estimates of groundwater supplies in other areas, in some of which the conditions are

* Lee, C. H., op. clt.
84 PLANTS AS INDICATORS OJ1 GROUND WATER

very different from those in Owens Valley. In the survey of the 

Mud Lake Basin, Idaho, tules were grown in a tank, and data were 

obtained on the aggregate discharge by evaporation and transpiration from this tank. In the same locality a record was obtained of 

the evaporation from a free water surface. For several years the 

discharge of ground water by mesquite and cottonwood trees and 

by sacaton and Mexican salt grass in San Pedro Valley, Ariz., has 

been studied by G. E. P. Smith, wlio has obtained, with waterstage recorders installed over dug wells, records of the daily fluctuation of the water table where these plants are feeding on ground 

water. Much work of the same 'kind has recently been done with 

good results in Escalante Valley, Utah, by W. N. White, of the 

United States Geological Survey, chiefly on alfalfa, salt grass, and 

greasewood.

The rate at which ground water is discharged by plants may reasonably be expected to vary with the plant species, the depth to the 

water table, the texture and alkali content of the soil, and the weather 

conditions. Each of these factors is somewhat complex, especially 

the last two. As it is hardly practicable to make tests for each of 

the great variety of conditions found in nature, it will be desirable 

to determine, so far as possible, what are the laws of transpiration by 

ground-water plants under the varying conditions.

Relation of rate of transpiration to kind of plant. As a rule the 

plants that grow in water and the ground-water plants that are 

most closely related to them probably discharge water freely. In 

the tank experiments at Mud Lake the aggregate discharge by transpiration from the tules and by evaporation from the water in which 

they were grown was much greater than the evaporation from a free 

water surface during the season of active growth. From June 13 to 

September 23,1921, the loss was 34.2 inclies from a free water surface 

in a tank on the land and 51.4 inches from a tank in which tules were 

grown in a submerged soil.66

The alkali-resistant ground-water plants are generally assumed to 

be economical in their use of water, but definite information is lacking as to the rate of ground-water discharge of the different species. 

The succulent alkali-resistant plants, fouch as pickleweed and samphire, probably do not discharge ground water rapidly, but in most 

arid regions they do not cover extensive areas and are not of leading 

importance in quantitative studies. Greasewood, however, covers very 

large areas, and its rate of transpiration is of major importance in 

quantitative studies. The rate of discharge by this species is now 

under investigation by W. N. White. The results already obtained

68 Stearns, H. T., and Bryan, L. L., Preliminary report on the geology and water 

resources of the Mud Lake Basin, Idaho: U. S. Geol. Survey Water-Supply Paper 560, 

pp. 97-102, 1925.
VALUE OF PLANTS AS INDICATOES 85

by him seem to indicate that greasewood is economical in its use of 

ground water, but in the aggregate discharges great quantities of 

ground water.

Salt grass is also of major importance in quantitative studies 

because of its very extensive occurrence in the areas of shallow 

ground water. The experiments by Lee in Owens Valley,- Calif., 

and by White in Escalante Valley, Utah, indicate that salt grass 

discharges ground water freely, and the growth it makes under 

favorable conditions also indicates free transpiration. Alkali sacaton likewise makes a good growth and probably discharges considerable water.

Mesquite is another ground-water plant of great importance in 

quantitative studies, for it doubtless disposes of vast quantities of 

ground water in the areas in which it flourishes. Its large and luxuriant growth in tracts having favorable conditions of ground water 

and soil indicates that it has a high transpiration, and this indication 

is corroborated by the recent investigation by G. E. P. Smith. As 

mesquite can also effectively resist drought when necessary, it is 

believed to have an unusual capacity to adapt itself to varying conditions. Apparently it uses water lavishly when opportunity affords 

or sparingly when the supply is restricted.

The investigations by White indicate that alfalfa, when growing 

as a ground-water plant, uses water in large quantities.

Relation of rate to depth of water table, A controlling factor in 

the water supply of ground-water plants is the depth to the water 

table. In this respect there is an analogy between the living plant 

that pumps up ground water for its use and the mechanical pumping apparatus that lifts ground water for the use of vegetation that 

is to be irrigated. In both cases the limiting condition is the lift 

required, the limitation in the first case being physical or biologic 

and in the second economic that is, the cost of pumping. The 

individual plant or the individual pump draws upon a vast reservoir o'f water that is but little affected by its operation. In both 

cases, however, the aggregate withdrawal by all the plants or pumps 

will lower the water table and thereby regulate the rate of withdrawal.

As has been shown, for each ground-water species there is an approximate limit of depth from which it can lift ground water. As 

in every area the depth to the water table changes gradually from 

place to place, there is a zonal arrangement of the different species 

of ground-water plants according to their different depth limits. 

Within these limits the rate at which the plants can draw up ground 

water varies inversely with the depth to the water table beyond a 

certain optimum depth. Evidence of this relation between rate of
86 PLANTS AS INDICATORS OP GROUND WATER

discharge and depth to the water table is furnished especially by salt 

grass, mesquite, and alfalfa. (

Lee found that in the salt-grass areas of Owens Valley the aggregate soil and vegetal discharge of ground water decreased in proportion as the depth to the water table increased, to a depth of about 8- 

feet, where the discharge became negligible. Application of this law 

to the figures obtained with the water table at several different depthsgave a maximum discharge, with the water table virtually at the 

surface, of 48 inches from April 1 to September 30 and 11 inchesfrom October 1 to March 31. This computed maximum discharge 

was about equal to the evaporation from a free water surface during 

the summer, but only a little more than one-half the evaporation from: 

a free water surface during the winter, when there was little or notranspiration. This fact and the results from one tank without vegetation suggest that during the summmer about half of the loss may 

have been occasioned by transpiration of the salt grass.

The maximum discharge by mesquite occurs where the water table 

is some distance below the surface. This optimum depth varies with 

the character of the soil but is generally 10 feet or more. From the 

optimum depth, where the mesquite may have a heavy growth, it 

generally becomes more stunted and scattered as the depth increases,, 

until at the limiting depth there is likely to be only a meager growth 

of small bushes. The range in size is doubtless due to a difference 

in the rate at which the mesquite can draw up water and serves as a 

rough measure of the relative rate of ground-water discharge.

Alfalfa will lift ground water from considerable depths and may 

produce crops of seed and some hay where it depends on a groundwater supply, but it will not make the growth on ground water that 

it would if it were well irrigated, doubtless because of its incapacity 

to lift water from the water table as rapidly as it could absorb water 

from a moist soil at the surface. Like mesquite, it has an optimum 

depth of water table. If the water table is nearer the surface than 

the optimum depth the alfalfa suffers for want of aeration; if it is 

farther below the surface the alfalfa is more severely handicapped 

by inadequate water supply. However, even at the optimum depth 

the growth is not as rapid as under ample irrigation, presumably 

because of the limitation in the available water supply.

The inverse relation between discharge of ground water and depth 

to ground water is doubtless applicable to most ground-water plants,, 

but it is probably not generally a simple, inverse proportion such as 

was found for salt grass in Owens Valley.

Relation of rate to evaporativity. In a cogent discussion of the 

rate of transpiration, G. E. P. Smith 67 showed that researches by

67 Am. Soc. Civil Eng. Trans., vol. 78, pp. 226-230, 1915.
VALUE OP PLANTS AS INDICATOES 87

I\ Shreve, B. E. Livingston, and Edith B. Shreve, of the Desert 

Botanical Laboratory,68 and by G. F. Freeman, of the Arizona Agricultural Experiment Station, indicate that under similar conditions 

of soil moisture the ratio of transpiration to evaporation from a free 

water surface tends to be a constant. This principle of a constant 

ratio, or of equal "relative transpiration," leads to two important 

conclusions. To the extent that it is correct it eliminates from many 

discussions complex climatic factors such as light, air pressure, temperature, and humidity and bases estimates of transpiration on the 

more easily measured evaporativity, or evaporation from a free 

water surface. Moreover, it leads to the conclusion, as stated by 

Shreve, that " it is the desert plants in which the rate of transpiration is high and the rain-forest plants in which it is low, which is 

quite the reverse of the commonly accepted view." A well-known 

experiment in Austria indicated that in the growing season of six 

months a beechwood forest transpires the equivalent of a layer of 

water 22 inches deep. Applying the principle of equal relative 

transpiration to this experiment, Smith showed that to obtain the 

rate of transpiration in arid regions, where the evaporativity is 

about two and one-half times as great, this figure must be multiplied 

by about 2%, giving about 55 inches. He further expressed the 

opinion that 55 inches depth of water a year probably represents 

fairly well the loss by transpiration from the cottonwood trees and 

that the loss from the mesquite forest, on account of the smaller leaf 

expanse, is perhaps half as great as that from the cottonwood. He 

called attention to the power of desert plants to reduce transpiration 

when necessary, but concluded that there is no evidence that this 

power is exercised by trees growing on the bottom lands, where the 

roots are bountifully supplied from below the water table. Later 

experiments by Smith, already cited (p. 84), support his belief 

that the transpiration of desert plants that feed on ground water 

is relatively high.

Relation of rate to quantity of dry 'matter. The water requirements of many crop plants and of some grasses and weeds have been 

determined, in various experiments, as the ratio of the weight of 

water absorbed by the plant during its growth to the weight of the 

dry matter produced, generally exclusive of the roots. In a large 

series of experiments made at Akron, Colo., by Briggs and Shantz,69 

rather wide differences were found in this ratio for different kinds 

of plants. Under the conditions of the experiments the average ratio 

for several varieties of alfalfa was found to be 831, which means that

68 Shreve, F., The transpiration behavior of rain-forest plants: Carnegie Inst. Washington Yearbook 12, pp. 74-76, 1913.

» Briggs, L. J., and Shaqtz, H. L., Relative water requirements of plants: Jour. Agr. 

Research, vol. 3, pp. 1-65, 1914.
88 PLANTS AS INDICATOKS OF GKOUND WATEE

an average of 831 tons, or 0.637 acre-foot, of water was absorbed by 

the alfalfa plants for each ton of dry alfalfa hay that was produced. 

If this method could be applied to ground-water plants it would 

furnish a convenient means of estimating their discharge of ground 

water. Whether it could be successfully used with woody perennials 

such as grease-wood and mesquite, however, is uncertain. In the areas 

of deep-rooting ground-water plants, where the water table is at 

considerable dSpth, all the ground-water discharge could be determined by this method, but in the areas of very shallow ground water 

the method would be inadequate in that it would fail to take account 

of the evaporation from the soil. On the other hand, deductions from 

the vegetal discharge would have to be made in some localities for 

soil moisture furnished by rain, snow, and flood water. This subject 

is under investigation by W. N. White in the Escalante Desert, Utah.

DEVELOPMENT OF GROUND-WATER PLANTS OF 

ECONOMIC VALUE

THE PROBLEM

The extensive investigations of the United States Geological Survey have shown that very large supplies of ground water occur in 

practically all the western States. In California about 1,000,000 

acres is irrigated with ground water pumped from wells, but in the 

other arid States comparatively little irrigation has hitherto been 

accomplished with water from wells, because of the prohibitive cost 

of pumping, and most of the annual supply of ground water goes to 

waste or supports plants of very low value. The investigations in 

Big Smoky and Steptoe Valleys, Nev., indicate that not far from 10 

per cent of the drainage basins of these valleys contain plants that 

feed on ground water. If these basins have anywhere near average 

conditions it follows that there are a few million acres of groundwater plants in Nevada alone. A part of this land is alkaline, but 

much of it has good soil.

Pumping water for irrigation is expensive, even where the lift is 

not great. The ground-water plants, however, lift the water without cost, and if plants of this kind, that are of economic value can 

be developed, the means will be at hand for utilizing vast quantities 

of water that now virtually go to waste and of making hundreds of 

thousands of acres of desert land productive. There are two possible methods of achieving the desired result (1) by developing 

more valuable varieties of certain established ground-water plants 

that already have some economic value, and (2) by developing 

ground-water varieties of certain valuable plants that already have 

some ground-water tendencies. With the first method it might, for 

example, be feasible to select and develop the best of the native
DEVELOPMENT OP GROUND-WATER PLANTS 89

grasses that feed on ground water; with the second it seems reasonable to expect that a variety of alfalfa can be developed that will 

lift ground water at a more rapid rate and from a greater depth 

than the varieties of alfalfa that are raised on irrigated land. Bermuda grass and pecan trees are also examples of promising groundwater plants of economic value. The following account of the successful use of ground water by alfalfa without pumping in the 

Escalante Valley, Utah, was kindly prepared for this paper by 

Walter N. White, of the United States Geological Survey. It is very 

suggestive of what may eventually be accomplished.

ALFALFA AS A GROUND-WATER PLANT

By WALTER N. WHITE

The fact that ground water is capable of maintaining deep-rooted 

plants in areas of deficient rainfall is illustrated by agricultural 

operations in Escalante Valley, near Milford, Utah. There the 

production of alfalfa seed with moisture derived from ground water 

has apparently passed the experimental stage and reached one where 

a reasonable degree of financial success is assured. The industry has 

been developed as the result of the experience of one rancher, and 

the story is rather romantic. The rancher was very poor, having 

lost practically all he had in a vain attempt at dry farming on 

a ranch about 5 miles south of Milford. A few head of mortgaged 

cattle remained, and in the spring, of 1919 he was pasturing this 

stock on lands near his homestead, all of which had been abandoned 

and most of which had previously been settled by dry farmers. One 

of the tracts, the S. y2 sec. 31, T. 28 S., E, 10 W., owned by the 

Beaver County Irrigation Co., had been irrigated and planted to 

alfalfa during the season of 1917 and then abandoned as a result 

of loss by the company of its water right in Beaver River by an 

adverse court decision promulgated in the winter of 1917-18. The 

rancher noticed to his surprise that a scattering growth of alfalfa 

among the greasewood and weeds, with which this half section was 

now covered, was increasing in thickness and vigor, although not a 

drop of water had been applied to the land in nearly two years. He 

decided that the alfalfa would provide considerable pasturage for 

his stock, and accordingly in the spring of 1919 he leased the tract 

from the company for two years, the consideration being that he 

was to keep the fence in repair. During the summer of 1919 he 

partly removed the greasewood and weeds from the land and grazed 

it sparingly, and in the fall he cut the alfalfa and obtained a crop 

of seed which sold for $3,000. In the following year the seed crop 

brought about $5,000. All this was accomplished with compara-
90 PLANTS AS INDICATORS OP GROUND WATER

tively little cash outlay or labor, and in the brief period of two years 

the rancher rose from poverty to a state of comparative prosperity. 

This experience created considerable excitement, and the reputation 

of sec. 31 was established throughout southwestern Utah, thereby 

creating a considerable boom for the Milford district. The prospect of obtaining a highly profitable crop without artificial irrigation or at least without irrigation after the crop was started was an 

attractive one. It was clear to all that the alfalfa in sec. 31 owed its 

life to the fact that the roots penetrated to the water table. However, 

it was also clear that if agricultural operations of this kind were to 

be extended, the alfalfa must be irrigated during the period while it 

was getting its start and its roots were penetrating to ground water. 

No surface water was available, and accordingly pumping from 

wells was resorted to.

During 1919 and 1920 six pumping plants were installed in the 

locality, and there has been a slow but steady pumping-plant development ever since. In 1923 there were 20 pumping plants in operation and about 900 acres in alfalfa which had been started by 

irrigation from these plants. In that year about 600 acres was irrigated from these plants, but the remaining 300 acres was not 

irrigated because the alfalfa had reached ground water and was able 

to subsist without artificial irrigation. This subirrigated acreage 

does not include the 240 acres of alfalfa seed land in sec. 31, in which 

the alfalfa got its start from one season of surface irrigation in 1917.

The reported yields of alfalfa seed from the S. % sec. 31 in the 

period 1920 to 1923 are: 272 bushels from 240 acres in 1920, 600 

bushels from 240 acres in 1921, 701 bushels from 160 acres in 1922, 

and TOO bushels (estimated) from 160 acres in 1923. Comparable 

yields were reported from other nonirrigated alfalfa-seed lands in 

the vicinity.

In 1923 the lands devoted to this industry were located within an 

area about 3 miles long and 1 mile wide, the center of which is about 

4 miles south of Milford, near the township corner common to Tps. 

28 and 29 S., Rs. 10 and 11 W. The area lies on the lowermost 

slopes of the Beaver River delta, slightly to the east of the trough 

of Escalante Valley and 10 to 15 feet above the lowest lands in the 

valley. It ranges from 4,970 to 5,010 feet'above sea level and slopes 

to the northwest with gradients ranging from 10 to 15 feet to the 

mile. Measurements of about 15 fairly evenly spaced wells in this 

area in the fall of 1923 showed depths to water ranging from 9 to 15 

feet. The water table rises 1% to 2y2 feet in the late winter and 

early spring. On lands where natural subirrigation has proved 

feasible the soil and subsoil down to the water table is a dark-gray
DEVELOPMENT OP GROTJND-WATEB PLANTS 91

clay loam or sandy loam and a black 

loam derived largely from decomposed 

peat. Attempts to extend the cultivation 

of subirrigated alfalfa to adjoining areas 

where the subsoil is gravelly have not 

proved successful, although the depths to 

ground water in these areas are no greater 

than in the area where success has been 

attained.

Sagebrush forms the dominant vegetation, but unused lands cleared of sagebrush several years ago now carry a fairly 

vigorous growth of greasewood. A series 

of tests with the electrolytic bridge in the 

area shows that the soil does not contain 

excessive amounts of alkali, though the 

alkali content is near the danger line for 

young alfalfa, the average for 10 tests 

of soil to a depth of 5 feet being 0.39 per 

cent.

Figure 15 shows the root system of 

an alfalfa plant in a field near Milford 

that is naturally subirrigated. The soil 

penetrated by this root system to a depth 

of Sy2 feet is gray clay loam and black 

peaty loam. Below this depth it consists of coarse sand and gravel. During 

a part of the growing season a considerable portion of the root system is below 

the water table. In the spring and early 

part of the summer, when the water table 

is at depths less than 8y2 feet, the growth 

of alfalfa plants in the immediate vicinity of the excavation is rapid and 

vigorous. Later in the season, however, 

the water table drops into the gravel, 

and then the plants assume a withered 

appearance and do not make much more 

growth. 12" 9" 6" 3" 0 3" 6" 9"

i i i i i i. i ji_

FIGUKB 15. Diagram of the root system of an alfalfa plant on the farm of W. BT. 

Hendrickson, in the NE. % sec. 36, T. 28 S., R. 11 W., Escalante Valley, Utah. The 

alfalfa was planted in 1922 and was irrigated the first season only. The capillary 

fringe is 3% feet or a little more in thickness. The root system was excavated and tiredrawing made by O. E. Meinzer and W. N. White, July 13, 1927. Dates Indicate levels. 

of water table

54380 27 7

INDEX

Page

Acknowledgments for aid__________. 15 

Africa, Southwest, plants that indicate

water in.. ___ ___. 10 

Alfalfa, growing of, with ground water___ 8&-91 

raised near Milford, Utah, plate showing- 54 

relation of, to ground water_ ____ 54-56,67 

soil favorable for...____________ 90-91 

water absorbed by--..__________ 87-88 

Allenrolfea occidentalis. See Pickleweed. 

Amy, F., cited.--.._....___ ... 9 

Areas of transpiration of ground water, determination of.____________ 82-83 

Arrow weed, relation of, to ground water.... 31,77 

Artemisia tridentata. See Sagebrush. 

Atrivlex. See Saltbushes.

Baccharis glutinosa. See Batamote. 

Batamote, relation of, to ground water 31-32,57-58 

Beechwood trees, rate of transpiration from.. 87 

Big Smoky Valley, Nev., birch trees in, plate

showing.._..__________ 54 

relation of ground-water plants to depth

of water table in.. _ , 76 

relation of ground-water plants to mineralization ofwaterin.._... 79,80,81 

wind-built mound occupied by greasewood in, plate showing..____ 40 

Bigeloeii hartwegii. See Qoldenrod, rayless. 

Birch, adaptation of, to both humid and arid

regions....___________. 71-72 

thicket of, in Big Smoky Valley, Nev.,

plate showing,_________ 54 

Birch Creek valley, Nev., vegetation in, plate

showing.____________. 6 

Botanists,,work of, on plants of arid regions.. 10-13 

Brown, John S., cited.. __________ 51,52,61 

Bryan, Kirk, cited-______________ 64 

Buffalo berry, occurrence of-.._______ 59 

Burroweed, relation of, to ground water__ 29

Cane, relation of, to ground water. _____ 17 

Cannon, W. A., cited..-..__.-.-...__ 3-4,64 

Capillary fringe, water drawn from_____ 68 

Carnegie Institution of Washington, work in

Desert Botanical Laboratory of.. 12-13 

Cat-tails, relation of, to ground water____ 16-17 

Cettis. See Hackberry.

Chamiso, relation of, to ground water, .'i__ 33-36 

Chilopsis linearis. See Desert willow. 

Chlorides in sap of plants, tests for._____ 70 

Chrysothamnus. See Rabbit brush. 

Cinquefoil, occurrence of..__.____ 60 

Clay, availability of water limited by___ 69,74 

Clayton Valley, Nev., ground-water plants

near well in..._.______ 79 

Cottonwood, growth of, in southeastern California, plates showing_____. 64 

relation of, to ground water. ..___ 58-59,67

Page

Coulter, J. M., cited.--...._.___-_. 11 

Coville, F. V., work of.___ _. _--._._ 12

Covillea tridentata. See Creosote bush. 

Creosote bush, occurrence of...___ 66 

Cuba, indicators of ground water in 61 

palm trees in areas of shallow ground

water in, plates showing.. 55

Dasiphora fruticosa. See Cinquefoil.

Death Valley, Calif., mesquite in...... .. 48-49

Definitions of terms...______ 1-2 

Depth to water table, indications of, by special plants_____________ 74-77 

Desert willow, relation of, to ground water.. 57-58 

Distichlis spicata. See Salt grass. 

Divining rod, attitudes of authors toward... 9 

Dondia torreyana. See Seepweed. 

Douglass, A. E., cited 5-6 

Drought-resistant plants, relations of.. 70-71 

Dry periods, growth by some plants during.. 6-6 

use of ground water during. 4-5 

Dunes, due largely to mesquite, plate showing.._____ . 54

Elderberry, occurrence of 59 

Elymus condensatus,. See Rye, wild. 

Engelmann spruce, relation of, to ground

water........-..--_.... 63

Eragrostis obtusiflora. See Salt grass, Mexican. 

Escalante Desert, Utah, alfalfa raised in . 55 

Estancia, N. Mex., alfalfa raised at 55

Geological Survey, recent publications of, 

that deal with ground water in 

desert regions 14 

Gila River valley, Ariz., mesquite in 49-51 

Qoldenrod, rayless, occurrence of. 31 

Gooseberry, occurrence of. 59 

Greasewood, big, connection of young

plants with older ones. 71

big, occurrence of 27

relation of, to ground water 37-42,

68,77-81,84-85

wind-built mound occupied by, plate

showing... 40

little, occurrence of.... .... ... 39,66

Ground-water habit, evidence of. 2-8

Hackberry, occurrence of 60 

Havard, V., on the habit of the mesquite 48 

Heliotrope, wild, occurrence of..... 29 

Heliotropicum curassavicum. See Heliotrope,

wild.

History of the subject 8-14 

Humid regions, adaptation of plants of,

to arid regions....__.. 71-72 

Hymenoclea monogyna. See Jacate.

Ironwood, occurrence of.. 66

93
94 INDEX

Page

Jacate, occurrence of.___............... 32

Juncus. See Rushes.

Kearney, T. H., and others, cited____.. 4-5,

27-28,39-41

Mesquite, contrast of, with desert vegetation, plates showing.. _____.. 40,54 

deep roots of, plates showing..____ 40 

plants associated with__________ 45 

relation of, to ground water.. 42-54,67,77-81,85 

running, in southeastern California, plate

showing______________ 40 

Milford, Utah, raising of alfalfa seed near_ 89-91 

Mink, O. M., cited.......-...----.._...... 63

Mohave Desert, Calif., mesquite in____ 54 

mesquite in, plate showing...______ 40 

Mohave River valley, Calif., dunes in, plate

showing..._________.... 54

zones of vegetation in, plates showing. 6,40,54

Oaks, occurrence of.______________ 62-63

Pahsimeroi Valley, Idaho, cottonwood in_ 58 

fluctuation of water table in.. ___ __ 68 

Palm trees, in areas of shallow ground water,

plates showing__________ 54,55 

relation of, to ground water_____ 60-61,77 

Palo verde, occurrence of..__..______ 66 

Papago country, Ariz., mesquite in____ 52-53 

Paramelle, Abbfi, cited. ___________ 8-9 

Parish, S. B., cited.......................... 32

Phragmites. See Reed grass.

Phreatophyte, definition of__________ 1 

Picea engelmanni. See Engelmann spruce. 

Pickleweed, relation of, to ground water.... 25-28,

68-70,77-81

Pine trees, relation of to ground water ___ 63-64 

Plants, as indicators of ground water, history

of the subject__________ 8-14 

as indicators of ground water, value of_ 72-73 

distribution of, with regard to depth to

 water______________ 6-7 

ground-water, capacity of, for resisting

drought....,.. ................ 70-71

grouping of, as to use of ground water.. 1-2,4-8 

species of, that habitually feed on ground

water______1_________ 15-64 

that do not habitually feed on ground

water, relations of.._______ 65-66 

that have easy access to water, divisions

of................................ 67

useful, possibility of growing, on ground

water________________ 56 

Platanus wrightii. See Sycamore. 

Playas Valley, N. Mex., mesquite in..___ 49 

Pluchea sericea. See Arrow weed. 

Poplars, in Mohave River vaDey, Calif., plate

showing______________ 40 

relation of, to ground water_______ 58-59 

Populus. See Cottonwood and Poplars. 

Prosopis. See Mesquite. 

Purslane, lowland, occurrence of_______ 29

Quail brush, occurrence of.__________ 59 

Quality of ground water, indicators of..__ 77-81 

Quantity of ground water, estimation of, from

transpiration by plants..____ 82-88

Page

Quercus. See Oaks.

Questions that deserve further study........ 14-15

Rabbit brush, relation of, to ground water.. 29-31,

77-80 

Ralston Valley, Nev., ground water plants

near well in____________ 79 

Rate of transpiration of ground water, determination of..._.________. 83-88 

relation of depth of water table to____ 85-86 

relation of evaporativity to..____..-. 86-87 

relation of kind of plant to...__ __.... 84-85

relation of quantity of dry matter to_.. 87-88 

Reed grass, relation of, to ground water. 17,77 

Roots, length of, where water lies deep...... 3-4

Roses, occurrence of-.--...__ -..-... 60 

Rushes, relation of, to ground water___ 16-17,77 

Rye, wild, relation of, to ground water. 17-18,77

Sacaton, alkali, relation of, to ground water. 23,25,

77-81 

coarse-top, occurren ce of... . 25

Sagebrush, relation of, to ground water 65

Salicornia. See Samphire.

Salix. See Willows.

Salt grass, growth of, over shallow ground

water, plate showing-.. 40 

occurrence of.._____.. .__.... 68 

rate of discharge of water by______.- 83 

relation of, to ground water__ 19-23,77-81,85 

Mexican, occurrence of.._.__.__.- 22-23 

 relation of, to ground water____.. 77-81

Salt-resistant plants, relations of. 68-70

Saltbushes, relation of, to ground water. 32-37

Salton Sea region, Calif., mesquite in . 51-52

Sambucus. See Elderberry.

Samphire, occurrence of 27,28 

relation of, to ground water....__..... 68-70

Sarcobatus baileyi. See Greasewood, little.

Sarcobatus vermiculatus. See Greasewood, big.

Scirpus. See Sedges.

Sedges, relation of, to ground water 16-17,77

Seepweed, relation of, to ground water__.. 28,33

Sequoias, relation of, to ground water 63-64

Sesuvium portulacastrum. See Purslane, lowland.

Seven Palms, a spring locality in southeastern California, plate showing...- 54

Shadscale, occurrence of.. ___ .... 27,32,37,39 

relation of, to ground water_______. 65-66

Shepherdia. See Buffalo berry.

Smith, G. E. P., cited................. 31-32,49,54

work of__________ . .. 13

Soil, relation of, to growth of plants 6-7

Spalding, V. M., cited...... . ... . 33,43-45

Sporobolus airoides. See Sacaton, alkali.

Sporobolus wrightii. See Sacaton, coarse-top.

Sudworth, G. B., cited.......... . 53

Sulphur Spring Valley, Ariz., mesquite in 46-48 

mesquite in, plate showing....____.. 40 

relation of ground-water plants to depth

of water table in__ . 75 

relation of ground-water plants to mineralization of water in.... __ 78,80,81

Sycamore, adaptation of, to both humid and

arid regions____________. 71-72 

occurrence of...-.-..___ . 62
INDEX 95

Page

Thompson, D. G., cited___________ 54 

Transpiration of ground water by plants,

determination of...... ____ 82-88

Trees, forest, growth of, in desert regions,

plates showing.. ____ 54

forest, relation of, to ground water_ 61-64,66

variation in rings of___________ 5-6

Tacson, Ariz., mesquite association near..... 43-45

Tularosa Basin, N. Mex., mesquite in___ 48 

relation of ground-water plants to depth

of water table in._ ____ 76 

relation of ground-water plants to mineralization o f water in.. ___ 79,80,81 

Tules, rate of discharge of water by.____ 84 

Tussock grass. See Sacaton, alkali. 

Tffphtt. See Cat-tails.

Value, economic, development of groundwater plants for_.....____ 88-91 

Vitravius Pollio, Marcus, cited_______ 8

Page

Wagner, P. A., cited. . 10 

Warming, Eugen, cited. 11-12 

Washingionia filamentosa. See Palm trees. 

Water, absorption of, by salt-resistant plants. 68-70 

Water-supply projects, relation of transpiration by plants to 82 

Water table, fluctuation of .. 67-68 

White, Walter N., Alfalfa as a ground-water

plant_______________ 88-91 

Willows, near springs in southeastern California, plate showing 54 

relation of, to ground water 56^58,77

Xerophyte, definition of.

Yerba mansa, occurrence of...__ 29 

Yuccas, occurrence of. 66

O