IT3

ants from 

eoyblac. Northeastern) Washin

1

Middle Eocene 

Dicotyledonous Plants from 

Republic, Northeastern Washington

By JACK A. WOLFE and WESLEY WEHR

U.S. GEOLOGICAL SURVEY BULLETIN 1597
DEPARTMENT OF THE INTERIOR 

DONALD PAUL MODEL, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

UNITED STATES GOVERNMENT PRINTING OFFICE: 1987

For sale by the Books and Open-File Reports Section, U.S. Geological Survey, 

Federal Center, Box 25425, Denver, CO 80225

Library of Congress Cataloging in Publication Data

Wolfe, Jack A., 1936-

Middle Eocene dicotyledonous plants from Republic, northeastern Washington.

(U.S. Geological Survey bulletin ; 1597)

Bibliography: p. 23

Supt. of Docs, no.: 119.3:1597

1. Dicotyledons, Fossil. 2. Paleobotany Eocene. 3. Paleobotany Washington (State) Republic Region. 

I. Wehr, Wesley. II. Title. III. Series.

QE75.B9 no. 1597a 557.3s 85-600197 

[QE983] [56T.3]
CONTENTS

Abstract 1

Introduction 1

Acknowledgments 2

Geologic occurrence 2

Systematic list of the Republic flora 3

Biostratigraphic considerations 4

Floristic and evolutionary considerations 7

Paleoclimatic inferences 10

Systematics 11

Lauraceae 11

Cercidiphyllaceae

Hamamelidaceae

Platanaceae 14

Fagaceae 15

Betulaceae 15

Myricaceae 16

Theaceae 16

Tiliaceae 16

Iteaceae 17

Rosaceae 17

Anacardiaceae 17

Burseraceae 18

Aceraceae 18

Sapindaceae 19

Cornaceae 21

Davidiaceae 21

Olacaceae 22

Incertae sedis 22

Systematic changes in other Eocene floras 23 

References cited 23

PLATES

[PLATES FOLLOW TEXT]

1. Phoebe and Sassafras

2. Sassafras

3. Cercidiphyllum

4. Langeria

5. Langeria

6. Macginitiea

7. Fagopsis

8. Alnus

9. Betula, Comptonia, and Ternstroemites

10. Ternstroemites and Tilia

11. I tea and Photinia

12. Rhus, Barghoornia, Koelreuteria, and Acer

13. Bohlenia

14. Cornus and Tsukada

15. Tsukada

16. Schoepfia and Republica

Contents iii
FIGURES

1. Map showing location of Republic fossil localities 2

2. Map showing location of some middle and late Eocene floras 5

3. Chart showing suggested correlations of some middle and late Eocene 

floras 7

4. Graph showing suggested temperature parameters for some Eocene 

floras 11

5. Sketch of fruits of Sapindaceae 20

TABLE

1. Occurrences of Republic dicotyledonous genera or related genera in extant 

and Neogene Mixed Coniferous forests 9

iv Contents
Middle Eocene Dicotyledonous Plants From 

Republic, Northeastern Washington

By}ack A. Wolfe and Wesley Wehr

Abstract

Twenty-four dicotyledonous species of megafossil 

plants from radiometrically dated early middle Eocene 

lake beds are discussed and illustrated. Six taxa are only 

generically determined and 18 are assigned to species. Of 

the genera represented, seven are extinct. Six genera are 

new: Langeria (Hamamelidaceae), Macginitiea (Platanaceae), Barghoornia (Burseraceae), Bohlenia (Sapindaceae), 

Tsukada (Davidiaceae), and Republica (Incertae sedis). 

Nine new species are described and five new combinations proposed.

The Republic flora represents a microthermal Mixed 

Coniferous forest that grew in an upland region that had 

an estimated altitude of about 700-900 m. The flora has 

few species in common with coeval lowland floras but 

shares several species with other Eocene upland floras. 

Analysis of the stratigraphic ranges of the Republic species 

indicates that several are useful in defining a biostratigraphic framework for upland Eocene floral 

assemblages.

The Republic flora represents a mixture of groups 

that were common during the Paleocene and early Eocene and groups that are of modern aspect. Analysis of 

the Republic lineages indicates that evolution and extinction in montane coniferous forests has proceeded at a 

greater rate than previously thought. Few of the Republic 

lineages survived into the Neogene, although some distant relatives now survive in broadleaved forests.

INTRODUCTION

Since I960, extensive application of radiometric dating techniques to volcanic rocks in parts of the 

western conterminous United States and adjacent 

Canada has shown that many floras once thought to 

be of Miocene age are of Eocene age (Axelrod, 1966). 

These floras occur in isolated depositional basins 

from British Columbia south into northeastern 

Washington, Idaho, western Montana, and northern 

Nevada a region that was apparently a significant 

upland during at least part of the Paleogene.

Our knowledge of Western North American Eocene floras and vegetation has been generally based 

on lowland assemblages from coastal or near-coastal 

areas (Potbury, 1935; Sanborn, 1935; MacGinitie, 

1941; Wolfe, 1968, 1977). We know little of the Eocene upland assemblages; indeed, only two Eocene 

upland assemblages, the late Eocene Ruby flora 

(Becker, 1961) and the late Eocene Copper Basin flora (Axelrod, 1966), have been described. Although 

some species from other upland Eocene floras have 

been described and tentative floral lists published, 

these floras have generally been neglected.

Of particular interest are two upland floras that 

have been radiometrically dated as middle Eocene: 

the Princeton flora and the Republic flora. The 

Princeton flora of southern British Columbia is based 

on a largely undescribed impression flora and a petrifaction flora that has received some attention. The 

majority of Eocene plant taxa in Western North 

America are, however, known from impressions, and 

previous concepts of floristics, evolution, and biostratigraphy are largely based on the impression 

floras. The second known early middle Eocene impression flora comes from rocks in and near the town 

of Republic in northeastern Washington.

In this report, we will document many of the 

angiosperm taxa present in the Republic flora and 

discuss their biostratigraphic, floristic, evolutionary, 

and climatic significance. The conifers, although generically determined, are under study by 

H. E. Schorn, and thus will not be treated in this 

report. Members of Ulmoideae are under study by 

Robyn Burnham and are also not dealt with here. 

Numerous other angiosperm taxa (particularly members of Rosaceae) are represented by fragmentary 

material; although further collections will undoubtedly produce material sufficient for systematic treatment of these taxa, as well as adding other genera and 

species, we think that new additions will not significantly alter the discussions presented here.

Introduction 1
The first collection of fossil plants from the 

rocks exposed in the town of Republic, Wash., was 

made by Waldemar Lindgren in 1902. Although 

Lindgren submitted the fossils to F. H. Knowlton, no 

description of the Republic plants appeared until 

E. W. Berry's (1929) brief account of a few Republic 

species. R. W. Brown (1935, 1937, 1939) also treated 

some of the Republic flora in a series of short reports. 

In 1965, in conjunction with geologic mapping in the 

Republic area by R. C. Pearson, Wolfe made collections from two new localities (Resner Canyon and 

Graphite Creek). Since 1977, Wehr has made extensive collections at the main locality at Republic.

ACKNOWLEDGMENTS

Assisting Wehr were Kirk Johnson and Michael 

Spitz, as well as many of the local residents, in particular: Elaina and Terry Koepke and Chester ("Sam") 

and Julie Jenkins and their children. Significant additional material was obtained by Steve and Andy 

Mannery of Bellevue and Janet and John Nicholas of 

Issaquah. Guy Anderson has been a source of continual encouragement for Wehr's Republic work.

We wish to acknowledge the considerable 

assistance of Scott L. Wing. Wing has not only discussed many of the evolutionary problems involved 

in the study of the Republic flora, but he has also 

assisted in unraveling some of the taxonomic problems. We have also had many useful discussions with 

H. D. MacGinitie on problems relating to Eocene 

plants and interpretations of their paleoclimatic 

significance.

GEOLOGIC OCCURRENCE

The Paleogene sequence in the Republic region 

consists of, in ascending order, the O'Brien Creek 

Formation, Sanpoil Volcanics, and Klondike 

Mountain Formation (Pearson and Obradovich, 

1977). The O'Brien Creek is largely water-laid tuffs 

and conglomerates, and marks the beginning of 

Tertiary volcanism in the region. The Sanpoil, which 

conformably overlies the O'Brien Creek, represents a 

widespread volcanic unit of flows and breccias that 

were derived from numerous vents. This period of 

extensive volcanism is radiometrically dated at about 

51-52 m.y. (Pearson and Obradovich, 1977).

A period of erosion followed the eruption of the 

Sanpoil Volcanics. During this period, extensive 

faulting resulted in the formation of grabens 

(Muessig, 1967). The Klondike Mountain Formation 

represents rocks that were locally deposited into 

these grabens. The lower part of the Klondike Mountain generally contains lacustrine rocks, and the middle and upper parts contain flows and coarse pyroclastic deposits.

The three localities from which the Republic 

assemblage was collected are all in the lower part of 

the Klondike Mountain Formation (Pearson and 

Obradovich, 1977). In the vicinity of Republic, the 

basal unit of lake beds was recognized by Muessig 

(1967) as the Tom Thumb Tuff Member, but Pearson 

and Obradovich (1977) didjiot formally distinguish 

members in the Klondike Mountain in the region 

northwest of Republic.

The lacustrine rocks that form the lower part of 

the Klondike Mountain Formation are interpreted to 

represent sediments deposited in lakes that were 

formed by damming from gravity slide deposits of 

pre-Tertiary rocks (Pearson and Obradovich, 1977). 

The source of the pre-Tertiary rocks was apparently 

the horst that is located between the Republic and 

Torada grabens (fig. 1). This would indicate that, at

119°00' 118°45'

49W

48°45'

10 MILES I I , , 1 1 , , , , 1

D 5

1 

10

I 

15 20 KILOMETERS

Figure 1. Location of Republic fossil localities. Stippled 

area denotes distribution of the Klondike Mountain Formation; heavy lines indicate contacts bounded by faults. 

Triangles represent localities at which radiometric samples were obtained. (Modified from Pearson and 

Obradovich, 1977.) Numbers refer to U.S. Geological Survey Paleobotanical Localities (Washington, D.C., catalog).

2 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
least locally, the horst was the site of mountains that 

had steep slopes. Additional evidence of considerable 

local relief is that in many areas the lacustrine rocks 

grade into nonvolcanic breccias and conglomerates.

Radiometric ages from the Klondike Mountain 

Formation range from 42.3 ±2.0 to 50.3 ±1.7 m.y. 

(Pearson and Obradovich, 1977). The three samples 

dated are from flows, and all samples came from the 

same stratigraphic position about 300 m above the 

plant-bearing unit in the Torada graben. Two of the 

samples had three analyses each; these analyses produced an average apparent age of 48.1 ± 1.8 m.y. for 

one sample and 49.4 ± 1.6 m.y. for the second sample. The third sample, on which two analyses were 

made, produced an average apparent age of 

42.4 ±1.8 m.y. The two older apparent ages are in 

close agreement and are accepted as the upper age 

limit for the Republic flora. Because the Sanpoil Volcanics are 51-52 m.y. old and are unconformable beneath the Klondike Mountain, the Republic flora is 

probably closer in age to 48-49 m.y. than to 

51-52 m.y.

The radiometric age of 56 m.y. reported by 

Axelrod (1966) for the Republic flora is anomalously 

old. The sample dated, however, came from waterlaid tuffs. The apparent age of Axelrod's is even older 

than that of the underlying Sanpoil Volcanics, and, as 

suggested by Pearson and Obradovich (1977), the 

sample dated probably contains contamination from 

pre-Tertiary rocks.

SYSTEMATIC LIST OF THE REPUBLIC FLORA

Coniferophyta 

Coniferae 

Coniferidae 

Taxales 

Taxaceae 

Taxusl sp. 

Gen. indet. 

Coniferales 

Taxodiaceae

Metasequoia occidentalis (Newberry) Chancy 

Sequoicf! sp. 

Cupressaceae 

Chamaecyparis sp. 

Thuja sp. 

Pinaceae

Abies milleri Schorn and Wehr 

Picea sp. 

Picea sp. 

Pinus sp. 

Pinus sp.

Pseudolarix americana Brown 

Tsugal sp.

Ginkgoidae 

Ginkgoales 

Ginkgoaceae

Ginkgo biloba Linnaeus 

Magnoliophyta 

Magnoliatae 

Magnoliidae 

Magnolianae 

Laurales 

Lauraceae 

Phoebe sp.

Sassafras hesperia Berry 

Hamamelididae 

Hamamelidanae 

Cercidiphyllales 

Cercidiphyllaceae 

Cercidiphyllum obtritum (Dawson) Wolfe and

Wehr

Hamamelidales 

Hamamelidaceae

Langeria magnifica Wolfe and Wehr 

Platanaceae 

Macginitiea gracilis (Lesquereux) Wolfe and

Wehr 

Urticales 

Ulmaceae 

Ulmus sp.

new genus aff. Zelkova sp. 

Fagales 

Fagaceae 

Fagopsis undulata (Knowlton) Wolfe and

Wehr 

Betulales 

Betulaceae

Alnus parvifolia (Berry) Wolfe and Wehr 

Betula leopoldae Wolfe and Wehr 

Myricales 

Myricaceae

Comptonia columbiana Dawson 

Dilleniidae 

Dillenianae 

Theales 

Theaceae

Ternstroemites sp. "A" 

Ternstroemites sp. "B" 

Malvanae 

Malvales 

Tiliaceae

Tiliajohnsoni Wolfe and Wehr 

Rosidae 

Rosanae 

Saxifragales 

Iteaceae 

Itea sp. 

Resales 

Rosaceae 

Crataegus sp. 

Crataegus sp. 

Crataegus sp. 

Photinia pageae Wolfe and Wehr

Systematic List of the Republic Flora 3
Potentilla sp. 

Prunus sp. 

Prunus sp. 

Prunus sp. 

Sorbus sp. 

Spiraea sp. 

Rutanae 

Juglandales 

Juglandaceae 

Caryal sp. 

Pterocarya sp. 

Rutales 

Anacardiaceae

.R/zws malloryi Wolfe and Wehr 

Burseraceae

Barghoornia oblongifolia Wolfe and Wehr 

Sapindales 

Aceraceae

"^4cer " arcticum Heer 

/leer sp. 

Sapindaceae

Bohlenia americana (Brown) Wolfe and Wehr 

Koelreuteria arnoldi Becker 

gen. indet. (samaras) 

Aralianae 

Cornales 

Davidiaceae

Tsukada davidiifolia Wolfe and Wehr 

Cornaceae

Cornus sp. 

Celastranae 

Olacales 

Olacaceae 

Schoepfia republicensis (La Motte) Wolfe and

Wehr 

Asteridae? 

Lamianae? 

Verbenales? 

Verbenaceae? 

"Holmskioldia " speirii (Lesquereux)

MacGinitie 

Incertae sedis (Hamamelididae?)

Republica hickeyi Wolfe and Wehr

The above list is not complete. At least ten other dicotyledonous taxa are represented in our collections by fragmentary or poorly preserved material. At 

least three of these are represented by leaflets that are 

probably assignable to Rutanae, and one taxon is 

represented by a samara of apparent sapindaceous 

affinity (see p. 19). We have also excluded fragmentary sedgelike remains from the list.

Among the generically determined material 

listed previously, Rosaceae are particularly significant. Except for the Photinia, we have decided to 

defer detailed treatment of this family; this deferral is 

partly due to our wish to obtain more extensive material and partly due to our opinion that a detailed 

systematic treatment of the Republic Rosaceae

should involve extensive reexamination of members 

of the family represented in other Eocene upland 

floras. The apparent modern aspect of the Republic 

and other Eocene Rosaceae at the generic level may 

be valid or may be an artifact of the lack of detailed 

comparative studies of fossil and extant rosaceous 

foliage.

BIOSTRATIGRAPHIC CONSIDERATIONS

Early workers generally considered the Republic flora to be part of the "Latah flora" and of Miocene age (Berry, 1929). Brown (1937), however, recognized that the Republic was perhaps more similar 

to the Bridge Creek flora; although then considered to 

be of early Miocene age, the Bridge Creek flora is 

now placed in the early Oligocene (Wolfe, 1981). 

Wolfe and Barghoorn (1960) suggested that the Republic flora was (1) older than the Bridge Creek and 

(2) correlative with both the Princeton, British Columbia, and Florissant, Colo., floras; although these 

are both Eocene floras, the Florissant (latest Eocene) 

is younger than the Princeton (middle Eocene). 

Axelrod (1966) considered the Republic to be approximately 56 m.y. old on the basis of the apparent 

age of a water-laid tuff in the Tom Thumb Tuff Member at Republic; if valid, the Republic flora would be 

of late Paleocene age.

Additional radiometric data indicate that (1) 

Axelrod's (1966) radiometric sample probably contains contaminants from underlying rocks, and (2) 

the Tom Thumb Tuff Member, which contains the 

Republic assemblages, is older than about 48-49 

m.y., but younger than 51-52 m.y. The difficulties 

encountered in prior age assignments of the Republic 

flora (and similar microthermal assemblages) strictly 

on the basis of paleobotanical evidence involve three 

factors. First, the systematic treatments of the component species of these microthermal floras have 

been poor; the putative occurrence of known Miocene species in these floras has been based on superficial examinations of the material. Detailed morphologic analyses indicate that none of the Republic 

species is conspecific with a Miocene species. Second, 

as Axelrod (1966) noted, altitude was generally ignored; an upland assemblage such as the Republic 

might be significantly different in both vegetational 

aspect and floristic composition from isochronous 

lowland assemblages. Third, major temperature fluctuations during the Eocene (Wolfe, 1971, 1978) have 

also been ignored; two assemblages might be vegetationally and, to some extent, floristically similar but 

represent different cool intervals. If valid radiometric 

data on these upland assemblages are lacking, then

4 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
the ages of these assemblages must be determined 

from careful systematic analyses of their component 

species. This report offers significant data on the occurrence of particular taxa and their stratigraphic distribution. Such data will allow us to understand the 

relative ages of fossil plant assemblages that represent

Eocene upland vegetation in Western North 

America.

The Republic is one of two upland floras that 

have radiometric ages that place the floras in the 

early middle Eocene (Wolfe, 1981). The other is the 

Princeton (fig. 2) in southern British Columbia.

_Stump Lake 

Quilchena 

Princeton

100 200 300 400 500 600 KILOMETERS

Figure 2. Location of some middle and late Eocene floras.

Biostratigraphic Considerations 5
Underlying the Princeton lake beds are volcanic 

rocks that have been dated at 51-52 m.y. (Hills and 

Baadsgaard, 1967), and an ash in the lower third of 

the lake beds has an apparent age of 50 m.y. (Rouse 

and Matthews, 1961). Thus the Princeton and Republic floras are approximately coeval.

The following angiosperm taxa occur in both 

the Princeton and Republic floras:

Sassafras hesperia,

Cercidiphyllum obtritum,

Macginitiea gracilis,

Alnus parvifolia,

Betula leopoldae,

Comptonia columbiana,

Rhus malloryi, and

Tsukada davidiifolia.

The Princeton and Republic occurrences are the 

youngest known for Macginitiea gracilis, and the oldest for Alnus parvifolia. The other five species may 

prove to be indices for the middle Eocene in this 

region. Cercidiphyllum obtritum and Comptonia columbiana both occur at Quilchena, British Columbia, 

Sassafras hesperia and Comptonia columbiana both 

occur in the Challis Volcanics at Thunder Mountain, 

Idaho. Sassafras hesperia occurs at Joseph Creek, 

British Columbia (also with Alnus parvifolia ).

The Yellowstone Park floras (Knowlton, 1899) 

are at about the early-middle Eocene boundary 

(MacGinitie, 1974). The younger assemblage contains Fagopsis undulata, which also occurs at Stump 

Lake, British Columbia. The Yellowstone floras represent warmer (lower altitude) vegetation than the 

Republic and similar floras, but even so some entities 

are conspecific. The following upland floras thus appear to be of middle Eocene age (fig. 3):

Republic, Wash.,

Thunder Mountain, Idaho,

Princeton, British Columbia,

Similkameen, British Columbia,

Quilchena, British Columbia,

Stump Lake, British Columbia, and

Joseph Creek, British Columbia. 

The Joseph Creek assemblage may be somewhat 

younger (late middle Eocene) than the Republic. This 

suggestion is based on the occurrence in the Joseph 

Creek of Bohlenia insignis, which is thought to be 

descended from the Republic B. americana.

Upland floras of late Eocene age are known 

from the conterminous United States. Axelrod (1966) 

has described the Copper Basin, Nev., flora and also 

gave a preliminary generic list of the Bull Run, Nev., 

flora; both have apparent radiometric ages of about 

40 m.y., which is early in the late Eocene.

The Salmon flora of the Challis Volcanics has 

been partially described (Brown, 1937). Although

Axelrod (1966) considered the flora to be middle Eocene, the floral locality is several kilometers, and 

across a major river valley, from the sample Axelrod 

had radiometrically dated; the relative stratigraphic 

relations of the floral and radiometric samples are 

unknown. The floristic composition of the Salmon 

assemblage is indicative of a late Eocene age. The 

Salmon lacks the species that are considered in the 

preceding to be diagnostic of a middle Eocene age. 

Significant is the occurrence in the Salmon of 

Mahonia and section Macrophylla of Acer. The oldest 

occurrence of Mahonia is in mesothermal assemblages of late middle Eocene age (Green River flora); 

in microthermal assemblages, Mahonia first occurs in 

the late Eocene (Copper Basin). Section Macrophylla 

is otherwise known only in early Oligocene (Bridge 

Creek) and younger floras, although the Salmon species is clearly distinct from younger species of the 

section. The Salmon flora is possibly isochronous 

with the latest Eocene Florissant flora but is of cooler 

and more mesic aspect than the Florissant.

The age of the Ruby flora (Becker, 1961) has 

not been firmly determined. The occurrence in the 

Ruby of Mahonia and Salix may indicate an age no 

older than late Eocene, when both genera first appear 

in microthermal climates. At least two Republic dicotyledonous species occur in the Ruby: Fagopsis undulata and Koelreuteria arnoldi.

None of the floras of the Clarno Formation of 

north-central Oregon are very similar to the Republic 

flora. Although the lowest flora near Mitchell, Oreg., 

is probably correlative with the Republic, only a few 

genera (Pinus, Ulmus, Rhus) and species (Alnus 

parvifolia, Macginitiea gracilis, uHolmskioldia" 

speirii) are common to the two floras. The Mitchell 

flora contains numerous broadleaved evergreens and 

represents mesothermal lowland vegetation. Above 

the Mitchell flora is the West Branch Creek assemblage. This assemblage is overwhelmingly broadleaved evergreen and represents Paratropical Rain 

forest during the late middle Eocene. Still younger, 

the early late Eocene John Day Gulch flora (Wolfe, 

1972, pi. 14) again has some broadleaved deciduous 

genera (but no species) in common with the Republic. The youngest Clarno flora, the latest Eocene Iron 

Mountain assemblage, represents Paratropical Rain 

forest (see Wolfe, 1971, for physiognomic analyses) 

and is also floristically dissimilar to the Republic.

Of particular interest is that the Republic flora 

includes taxa or lineages that in the lowland floras are 

not known to occur later than the early Eocene. 

Macginitiea gracilis occurs in the Paleocene and 

through the upper floral zone of the lower Eocene 

Willwood Formation (Wing, 1981). In the early middle Eocene, this species is apparently replaced by

6 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
WASHI

WESTERN

UNNAMED

KUMMERIAN 

STAGE

RAVENIAN 

STAGE

UPPER

O

5

LOWER

FULTONIAN 

STAGE

FRANKLINIAN 

STAGE

NGTON

EASTERN

REPUBLIC

BRITISH 

COLUMBIA

JOSEPH 

CREEK

PRINCETON, 

STUMP LAKE, 

QUILCHENA

OREGON

GOSHEN

CLARNO (IRON 

MOUNTAIN) 

COMSTOCK

CLARNO (JOHN 

DAY GULCH)

CLARNO (WEST 

BRANCH CREEK)

CLARNO 

(MITCHELL)

CALIFORNIA. 

NEVADA

LA PORTE, 

MOONLIGHT

LOWER 

CEDARVILLE, 

COPPER BASIN, 

BULL RUN

SUSANVILLE

IDAHO, 

MONTANA

RUBY 

SALMON

THUNDER 

MOUNTAIN

COLORADO, 

WYOMING

FLORISSANT

GREEN RIVER 

(PART)

YELLOWSTONE,

KISINGER

LAKES

AGE

(in Ma)

 35

1 

EOCENE .ATE 

 40 

1 

^ o«

EOCENE MIDDLE 

EARLY 

EOCENE 

(LATER PART)

Figure 3. Suggested correlations of some middle and late Eocene floras. Radiometric ages suggested for epochal and 

subepochal boundaries follow Armentrout (1981).

"Platanus" (= Macginitiea) browni (MacGinitie, 

1974) at low altitudes. Cercidiphyllum genetrix occurs in the Paleocene and into the upper floral zone 

of the Willwood (Wing, 1981); the genus is not found 

in floras such as the Kisinger Lakes (MacGinitie, 

1974). In the Republic, C. obtritum is thought to be 

descended from C. genetrix. "Ampelopsis" acerifolia 

has a known range of Paleocene through the lowest 

floral zone of the Willwood (Wing, 1981), and the 

probably congeneric "y4cer" arcticum is elsewhere 

known only from the early Eocene. The persistence of

these lowland taxa in the Republic may indicate that 

upland areas served as refugia.

FLORISTIC AND EVOLUTIONARY 

CONSIDERATIONS

The relations of the Republic dicotyledonous 

flora to present floristic regions are ambiguous. Some 

Republic genera are now exclusively east Asian: 

Cercidiphyllum, Pterocarya, and Koelreuteria. At 

least one, however, is exclusively New World:

Floristic and Evolutionary Considerations 7
Comptonia. Additionally, Bohlenia is most closely related to extant New-World genera; Tsukada is related 

to the Old-World Davidia. Most extant Republic genera are today both Old and New World. On the subgeneric level, the relations are also ambiguous; Tilia 

johnsoni is most closely related to extant Eurasian 

species, but Schoepfia republicensis is most closely 

related to extant North American species.

The origins of most Republic dicotyledonous 

lineages are, at best, obscure. Some lineages were 

probably present in North American vegetation of 

moderate to low altitude during the Paleocene and 

early Eocene; members of this category include: 

Cercidiphyllum obtritum, Macginitiea gracilis, 

Fagopsis undulata, Rhus malloryi, '"''Acer''' arcticum, 

"Holmskioldia" speirii, and Republica hickeyi. Other 

members of this category could include Langeria 

magnified, Alnus elliptica, and Betula leopoldae, but 

the relationships of these taxa to older taxa are 

unclear.

The Republic dicotyledonous flora includes 

some taxa that represent the oldest megafossil occurrence of their respective genera and whose antecedents are unknown. Included in this category are: Sassafras hesperia, Langeria magnifica, Tilia johnsoni, 

Itea sp., Photinia pageae, Barghoornia oblongifolia, 

Bohlenia americana, Koelreuteria arnoldi, Tsukada 

davidiifolia, and Schoepfia republicensis. Many of the 

remaining unstudied Rosaceae probably also should 

be included in this category. The general mesothermal to megathermal affinities of some Republic genera, as well as the occurrences in the lowland palynological record of Tilia and Anacalosidites, indicate 

that the following taxa also probably represent the 

Paleocene to early Eocene lowland group: Langeria 

magnifica, Tilia johnsoni, Barghoornia oblongifolia, 

and Schoepfia republicensis. The lack of earlier 

megafossil records for these lineages, however, makes 

it impossible to determine whether these lineages entered microthermal climates during the middle Eocene or earlier. Also unknown is whether the lowland 

antecedents in the lineages were sufficiently morphologically similar to be considered congeneric with 

their descendants.

One significant aspect of the Republic flora is 

the inclusion of now dominantly megathermal to 

mesothermal groups. Some members of Lauraceae 

and Theaceae are today found in microthermal climates, so the inclusion in the Republic of Phoebe and 

Ternstroemites is not anomalous. Burseraceae, 

Sapindaceae, and Olacaceae, however, represent 

"paleoecological dissonance," to use Woodring's 

(1960) term; members of these groups today are 

dominantly megathermal with some mesothermal 

(but no microthermal) outliers. Both Barghoornia

(Burseraceae) and Bohlenia (Sapindaceae) are extinct, a situation that might be expected for 

microthermal outliers of now dominantly megathermal groups.

Axelrod (1966, p. 53) considered the Republic 

and other upland floras to have a modern aspect, 

from which he suggested that little evolution has 

occurred in coniferous (or mixed broadleaved and 

coniferous) forests during the Tertiary. Of the 

broadleaved genera recognized by Axelrod (1966, p. 

45) as occurring in the Republic, a few do have a 

somewhat modern aspect: Sassafras and Comptonia. 

Some other genera listed, however, represent 

misidentifications; for example, the "Fagus" 

represents the extinct Fagopsis, the "Aralia" 

represents the extinct Macginitiea, the "Acer" 

represents seeds of an as yet undetermined genus 

(perhaps Sapindaceae), the "Dipteronia" represents 

the extinct Bohlenia, and the "Zelkova" represents an 

extinct genus of Ulmoideae.

The Republic broadleaved taxa exhibit little 

morphologic similarity to extant taxa. Cercidiphyllum obtritum is related to species such as C. genetrix; 

these represent an extinct group that was coeval with 

a group morphologically similar to the extant 

C. japonicum. Comptonia columbiana is a unique 

doubly serrate form, unlike many older and younger 

(including the extant C. asplenifolid) species of the 

genus. Tilia johnsoni resembles species of the extant 

subsection Reticulares that inhabit broadleaved deciduous forests in eastern Asia but does not resemble 

extant North American species.

Floristic comparisons of the Republic assemblage to the present flora of the Low Montane Coniferous forest of North America (table 1) indicate few 

similarities. Among the Republic dicotyledons that 

we have studied, some genera and generic pairs are 

found in both Eocene and extant floras, but the respective lineages are not phyletically related (table 1). 

Indeed, of the 25 reliably determined Republic dicotyledonous genera, only 4 now occur in Mixed Coniferous forest in Western North America, and only 10 

occurred in this vegetation in Western North 

America during the Neogene.

A thorough study of the Republic and other 

Paleogene Rosaceae will probably indicate a somewhat closer relationship between the Republic and 

younger microthermal floras than indicated in table 

1. Indeed it is the numerous diverse rosaceous types 

in the Republic that give the flora a "modern" aspect. 

The sources for many Neogene rosaceous lineages 

may well have been in the Eocene uplands of Western 

North America, but this suggestion requires further 

evaluation by detailed systematic treatment of rosaceous fossils.

8 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
Table 1. Occurrences of Republic dicotyledonous genera 

or related genera in extant and Neogene Mixed Coniferous forests___________________________

Extant Mixed Neogene Mixed

Coniferous Coniferous

forest, Western forest, Western

Republic North America North America

Phoebe

Sassafras

Cercidiphyllum

Langeria

Ulmus

"Zelkova"

Fagopsis

Alnus

Betula

Comptonia

Ternstroemites

Tilia

Itea

Photinia

Pterocarya

Rhus

Barghoornia

Acer

Bohlenia

Koelreuteria

Cornus

Tsukada

Schoepfia

Republica

Holmskioldia

Umbellularia

Quercus 

Alnus 

Betula 

Myrica

Heteromeles

Toxicodendron 

Acer

Cornus

Laurophyllum

Sassafras

Cercidiphyllum

Fothergilla

Ulmus

Zelkova

Fagus

Alnus

Betula

Comptonia

Tilia.

Heteromeles 

Pterocarya

Toxicodendron 

Acer

Cornus

The basic causative factor in the strong floristic 

difference between the Eocene and later Low Montane Mixed Coniferous forest is the major temperature shift at the end of the Eocene (Wolfe, 1978). 

This shift was to a high mean annual range of temperature (the warm-month temperatures were not significantly altered but the cold-month temperatures 

radically decreased), and led to the regional or total 

extinction of many woody broadleaved evergreen 

and broadleaved deciduous species and genera that 

were intolerant of intense and prolonged winters. The 

High Montane Mixed Coniferous forest was the predominant coniferous forest during the Oligocene and 

Miocene at high latitudes and at high altitudes at 

middle latitudes (for example, floras at Creede, 

Colo.). Only during the Miocene did areas suitable to 

Low Montane Mixed Coniferous forest become available as mean annual range of temperature decreased; 

floras of the later half of the Miocene on the Columbia Plateau (Blue Mountains, Thorn Creek, Trout

Creek) and Cascade Range (Hidden Lake) represent 

this vegetation. The broadleaved deciduous trees and 

shrubs in the Miocene coniferous forest show little 

phyletic linkage to those of the Republic flora, although some genera are common' to both assemblages. The persistent and important broadleaved deciduous adjuncts to the Miocene coniferous forest in 

the Pacific Northwest are Platanus, Ulmus, Zelkova, 

Alnus, Betula, Fagus, Quercus, Populus, Salix, Gary a, 

Pterocarya, and Acer, half these genera are absent in 

the Republic flora.

Comparison of the Republic flora to late Eocene microthermal floras (Salmon, Copper Basin, 

Ruby Basin) indicates some continuity of lineages; 

for example, Sassafras ashleyi and Bohlenia insignis 

are probably derived from species represented in the 

Republic flora, and Fagopsis undulata, Alnus 

parvifolia, and Koelreuteria arnoldi are represented in 

both middle and late Eocene floras. On the other 

hand, lineages represented by the Republic Langeria, 

Cercidiphyllum obtritum, Macginitiea, Comptonia 

columbiana, and "Acer" arcticum are unknown later 

than the middle Eocene.

Some groups represented in the Republic flora 

survived into the Oligocene microthermal flora in 

Western North America. Such groups include 

Bohlenia, Koelreuteria, and "Holmskioldia"', none pf 

these, however, are known in the Neogene of North 

America. Notable in the Republic flora is the absence 

of some groups that are now prominent in 

microthermal vegetation: for example, Ericaceae, 

Salicaceae, and Caprifoliaceae. In the instance of Ericaceae and Caprifoliaceae, these families are not conspicuous in microthermal vegetation until the later 

half of the Miocene. Salicaceae are present in mesothermal middle Eocene vegetation (MacGinitie, 

1974), but they are first known in microthermal vegetation in the late Eocene (Wolfe, 1977).

The data strongly indicate that microthermal 

vegetation in Western North America experienced 

considerable floristic change during the Tertiary. 

Various lineages became extinct at various times. 

Other lineages entered microthermal vegetation at 

different times during the Tertiary, some lineages for 

brief periods and other lineages remained for long 

periods during which diversification occurred. The 

fact that one species of a genus occurs in an Eocene 

microthermal assemblage and a second species of the 

same genus occurs in Miocene or Holocene 

microthermal vegetation is, by itself, no proof of genetic continuity and an inferred low rate of either 

evolution or floristic change in microthermal vegetation. An understanding of evolutionary rates and floristic continuity should be based on detailed morphologic analyses.

Floristic and Evolutionary Considerations 9
PALEOCLIMATIC INFERENCES

The present distributions of the extant species 

most similar to the Republic taxa cannot be used 

reliably to estimate paleotemperatures. Genera such 

as Ginkgo, Metasequoia, Cercidiphyllum, Sassafras, 

and Koelreuteria are now represented only in dominantly broadleaved forests. Some Republic taxa are 

members of extinct genera (Langeria, one member of 

Ulmoideae, Macginitiea, Fagopsis, Barghoornia, 

Bohlenia, Tsukada, Republica) and others (Ternstroemites) can only be assigned to form genera. Other Republic genera (Chamaecyparis, Abies, Pinus, 

Tsuga, Alnus, Acer, Tilid) occur in both dominantly 

broadleaved and dominantly coniferous forests, and 

at least one genus (Piced) is now confined to coniferous forests. Indeed, almost half the known Republic 

genera are today extinct or are monotypic or bitypic, 

which makes the present distributions of related taxa 

of doubtful value.

The Republic assemblage represents Mixed Coniferous forest from two lines of evidence. First, palynological samples contain 70 to 80 percent bisaccate 

pollen of Pinaceae (Wolfe, unpub. data). Second, the 

megafossil assemblage contains a diversity of members of Cupressaceae and Pinaceae: Chamaecyparis, 

Thuja, Abies, Picea, Pinus, Pseudolarix, and Tsuga. 

However, the megafossil samples are at most localities dominated by dicotyledonous leaves, and thus 

the Republic assemblage could be inferred (for example, Axelrod, 1966) to represent broadleaved deciduous forest with an admixture of conifers. This dominance of dicotyledonous leaves, however, is probably 

related to most of the fossils having been obtained 

from fine-grained lacustrine rocks that were deposited a considerable distance from shore. The organs of 

higher specific gravity (cones and detached needles of 

conifers) would probably settle out close to the shore, 

and the organs of lower specific gravity (dicotyledonous leaves and winged seeds of both conifers and 

dicotyledons) would probably float a considerable 

distance out into the lake(s). If only winged seeds are 

considered, the Republic assemblage was decidedly 

coniferous: the seeds of Pinaceae are much more 

abundant than are the winged fruits or seeds of dicotyledons (Ulmoideae, Betulaceae, Acer, Bohlenia, 

Koelreuteria).

The apparent absence of vines in the Republic 

megafossil assemblage is also significant. Wang 

(1961) noted the absence or paucity of vines in coniferous forests in comparison to the abundance of 

climbers in broadleaved forests.

The most abundant dicotyledonous leaves at 

the main locality at Republic are Alnus, Cercidiphyllum, Sassafras, Rhus, Ulmoideae, Macginitiea, and

Comptonia, all of which are represented by more 

than 20 specimens each. Represented each by 10 to 

20 specimens are Langeria, "Holmskioldia," sapindaceous samaras, and Bohlenia. At the Resner Canyon 

locality (11018), the abundant dicotyledonous leaves 

are Cercidiphyllum, Macginitiea, and Comptonia. 

The Graphite Creek locality (11019) has abundant 

Fagopsis but few other dicotyledonous leaves. The 

Graphite Creek assemblage was obtained from more 

arenaceous rocks than the main Republic or Resner 

Canyon assemblages and hence represents deposition 

closer to shore. Significantly, foliage of Chamaecyparis and Pinus is at least as abundant as that of 

dicotyledons at Graphite Creek.

Broadleaved evergreens are a minor element in 

the Republic assemblage, and include Phoebe, Ternstroemites spp., Photinia, and Republica. These may 

represent small trees or shrubs in the coniferous forest. In contrast, many of the broadleaved deciduous 

taxa probably were trees of the moist bottomlands or 

lakeside to streamside habitats. This is particularly 

true of Cercidiphyllum, Macginitiea, Ulmoideae, 

Fagopsis, and Alnus; members of these groups are 

typically abundant in many Paleocene and Eocene 

assemblages, which is indicative of tolerance to moist 

ground habitats that occur close to depositional sites.

The Republic assemblage thus has the following 

physiognomic features: (1) a diverse and dominant 

coniferous element, (2) a subsidiary but diverse element largely lakeside or streamside of broadleaved deciduous and deciduous gymnospermous 

trees, (3) a minor forest element of broadleaved evergreen and broadleaved deciduous small trees and 

shrubs, and (4) no vines.

The temperature parameters for Mixed Coniferous forest (fig. 4) indicate that the mean annual 

temperature was <13°C and the mean of the warm 

month was <20°C (Wolfe, 1979). Further, the broadleaved evergreen element indicates a cold-month 

mean of >1° to -2°C, and the diversity of the broadleaved element indicates a warm-month mean of 

>15°C. That is, the Republic assemblage represents 

Low Montane Mixed Coniferous forest (Wolfe, 

1979). In areas of this vegetational type, mean annual 

ranges of temperature are from 4° to 22 °C (or to 

19°C if the minimal cold-month mean is 1 °C).

Any further refinement of the Republic paleotemperature estimates must be based on consideration of the temperatures estimated for coeval lowland 

assemblages. The Republic is approximately coeval 

with the assemblages from the type section of the 

Fultonian Stage of the Puget Group (Wolfe, 1981). 

The physiognomy of the assemblages from this stage 

indicates a mean annual range of temperature of 4° 

to 5°C (Wolfe, 1978). Assuming approximately the

10 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
20

I* 15

m 10

I I I I I I I I I

NOTOPHYLLOUS BROADLEAVED 

EVERGREEN FOREST

UPPER fS. LOWER ( KISINGER 

FULTONIANJ I LAKES

\

MICROPHYLLOUS BROADLEAVED 

EVERGREEN FOREST

THUNDER ] 

MOUNTAIN!/

LOW COASTAL MIXED 

CONIFEROUS FOREST

i i i PVJ i i i i i i

5 10

MEAN ANNUAL RANGE OF TEMPERATURE, 

IN DEGREES CELSIUS

15

Figure 4. Suggested temperature parameters for some Eocene floras.

In calculating estimated paleoaltitudes, most 

important is that upland assemblages be properly calibrated in time with lowland assemblages. For example, if the Republic were compared to assemblages 

such as those of the lower part of the type section of 

the Ravenian Stage and the Steel's Crossing, a much 

higher paleoaltitude would be suggested. Early 

Ravenian assemblages are estimated to have a mean 

annual temperature about 1° to 8°C higher than 

Fultonian assemblages in the same area. The coolness 

of the early middle Eocene in contrast to the warmth 

of the late middle Eocene is also indicated in the 

marine record (Wolfe and Poore, 1982). The coolness 

of the late Ravenian relative to either the early 

Ravenian or the Kummerian Stage is also indicated 

in both marine and nonmarine environments.

SYSTEMATICS

same mean annual range for the Republic area during 

the early middle Eocene appears justified; although 

the Republic area is about 250 km farther from the 

coast and about 1 ° of latitude farther north than the 

Puget area, mean annual range of temperature tends 

to decrease with increasing altitude (Axelrod, 1966; 

Wolfe, 1979, fig. 1). Whereas the first two geographic 

factors would yield a higher mean annual range for 

the Republic than for the Puget Fultonian assemblages, the altitudinal difference would tend to negate 

the geographic factors.

We thus infer that the mean annual range of 

temperature for the Republic assemblage was most 

probably 5°C (certainly no more than 6°C). Given 

the other temperature parameters of Low Montane 

Mixed Coniferous forest, mean annual temperature 

was about 12° to 13°C (certainly no lower than 

11.5°C). Such temperatures occur today, for example, along the coast of southern Oregon and northern 

California (Wolfe, 1979, pi. 3), and, judging from 

data at lower altitudes, probably also occur in the 

Mixed Coniferous forest of Central America. Such 

areas rarely receive freezing temperatures.

The difference between the mean annual temperatures for the Republic (12°-13°C) and the coastal 

Puget Fultonian (17°C; Wolfe, 1978) assemblages allows an approximate estimate of the altitude of the 

Republic basin of deposition during the early middle 

Eocene. Assuming a lapse rate (that is, the rate of 

decrease in mean annual temperature with increasing 

altitude) of about 0.55°C/100 m, the Republic basin's altitude was between 727 and 909 m (2,375 to 

2,970 ft).

We have generally followed the system of terminology presented by Hickey (1973). In some respects 

we have not found the system entirely satisfactory for 

descriptive purposes, but the system is the most comprehensive that has been published. We have used 

"abmedial" in preference to Hickey's "exmedial" (to 

parallel abaxial and adaxial), and we prefer von 

Ettingshausen's (1861) "external secondary" vein or 

branch to Hickey's "secondary vein branch."

The specimens cited have been placed in the 

following institutions:

UCMP: University of California Museum

of Paleontology, Berkeley, Calif. 

USNM: United States National Museum,

Washington, DC, and

UW: University of Washington, Thomas 

Burke Memorial Washington State 

Museum, Seattle, Wash.

Family LAURACEAE 

Genus PHOEBE Nees

Phoebe sp.

Plate 1, figures 3-6

Discussion. In their typically linear shape the 

Republic leaves are similar to Cinnamomophyllum 

kushtakensis Wolfe. Venation below the fourth-order 

level is, however, indistinct, and we thus hesitate to 

assign the Republic leaves to any named species.

Most, if not all, species assigned to Cinnamomophyllum may represent Phoebe. This suggestion is based on Kostermans' (1961) conclusion that 

the tri-nerved species of extant Cinnamomum actually represent Phoebe.

Systematics 11
These leaves differ from the unlobed leaves of 

Sassafras hesperia in three regards: in the Phoebe, the 

shape is more linear, the first major lateral veins depart proportionately farther from the base, and these 

veins typically extend only about half the distance to 

the apex.

Specimens. USNM 32676-32679; UCMP 

9263, 9264.

Occurrence. Locality 8428.

Genus SASSAFRAS Trew 

Sassafras hesperia Berry

Plate 1, figures 1, 2, 7; Plate 2, figures 1-7

Sassafras hesperia Berry, 1929, p. 259, pi. 59, fig. 2.

Brown, 1937 (part), p. 174, pi. 53, fig. 8. 

Sassafras selwyni auct. non Dawson. Berry, 1926,

p. 114, pi. 14, figs. 1-4.

Discussion. In the breadth of the lamina, 

shape of the lobes, and departure of the two major 

lateral veins close to the base, the leaves from the 

Eocene on Joseph Creek, British Columbia (Berry, 

1926), are similar to our Republic specimens of Sassafras hesperia. As Brown (1937) noted, the type 

specimen of S. hesperia, although stated by Berry 

(1929) to be from the Latah Formation at Spokane, 

actually came from Republic. Axelrod (1966, p. 45), 

although calling the Republic flora Eocene, confused 

the issue of typology; in discussing S. hesperia, he 

(1966, p. 70) erroneously attributed this species to 

the Oligocene. This error is significant, because one 

of Axelrod's (1966) theses is that the Eocene montane 

species of a given genus are typically smaller leaved 

than Miocene species of the same genus, and he cited 

as one of his examples the size difference between the 

Eocene S. ashleyi Axelr. and the Miocene S. columbiana Chancy and Axelr. The leaves of S. hesperia are 

as large (indeed the lobe of one incomplete specimen 

is 13.5 cm long) as those of S. columbiana and larger 

than those of S. ashleyi.

Axelrod (1966, p. 70) suggested that the northern Eocene Sassafras may represent lobed Lindera. 

In lobed Lindera, a prominent secondary vein does 

not extend directly to the sinus; the vein entering the 

sinus is a branch of a tertiary vein.

The texture of Sassafras hesperia is typically 

very thick thicker than the Copper Basin S. ashleyi 

or S. columbiana. The thick texture may indicate an 

evergreen habit for S. hesperia. Although both extant 

species of Sassafras are deciduous, both deciduous 

and evergreen habits are found in Lindera and Litsea. The evergreen habit must occur in the ancestry 

of Sassafras, because such a habit is basic to 

Lauraceae.

Sassafras hesperia is one of the most common 

dicotyledonous leaves at Republic. The species also 

occurs in the Princeton and Joseph Creek assemblages. We reject the occurrence at Florissant 

(MacGinitie, 1953); the specimen on which the citation is based has external veins that approach the 

margin more closely than do the external veins of 

S. hesperia in several features.

The late Eocene Sassafras ashleyi Axelr. differs 

from S. hesperia in several features. As noted by Axelrod (1966, p. 70), S. hesperia has lobes that tend to 

be shorter and more abruptly acute, although this 

character intergrades (compare Axelrod's pi. 15, fig. 7 

to our pi. 2, fig. 3). More significantly, in S. hesperia 

the secondary veins and their external veins tend to 

loop farther from the margin, the secondary veins 

tend to be brochidodromous (in S. ashleyi the secondaries thin markedly and are hence eucamptodromous), the tertiary veins are stronger and more 

percurrent, and the pair of major lateral veins typically depart closer to the base. All these characters 

overlap somewhat, and we suggest that -S. ashleyi is 

closely related and probably descended from S. 

hesperia.

Hypotypes. USNM 32680; UCMP 9265- 

9269; UW 31241, 39709, 39710, 39715, 39717, 

39720.

Occurrences. Localities 8428, 11018, 11019.

Family CERCIDIPHYLLACEAE

Genus CERCIDIPHYLLUM Siebold and Zuccarini

Cercidiphyllumobtri obtritum (Dawson) Wolfe and Wehr, n. comb.

Plate 3, figures 1-8

Populus obtrita Dawson, 1890, p. 82, text-fig. 12. 

Cercidiphyllum crenatum (Unger) Brown, 1935

(part), p. 575, figs. 1,6. 

Populus daphnogenoides auct. non Ward. Dawson,

1890, p. 83, text-fig. 13.

Supplementary description. Leaves simple; 

shape symmetrical; form very wide ovate; apex 

rounded to obtuse; base typically shallowly cordate to 

truncate; margin serrate, apical angle acute, serration 

type A-l to B-l, sinuses rounded to angular, spacing 

regular, teeth simple and with small apical glands; 

petiole normal, at least 4 cm long; primary venation 

actinodromous (basal to atypically suprabasal), perfect, reticulate, typically two strong and one weak 

pairs, midrib moderate, straight; first pair of lateral 

primaries curving smoothly or forking, extending at 

least three-fourths or more the distance to apex, typically slightly converging with medial secondary 

veins; second pair of lateral primaries curving 

smoothly, extending about one-third the distance to 

the apex, parallel to abmedial branches of first pair of

12 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
primary veins; typically three pairs of medial secondary veins, three to five pairs of abmedial branches of 

first pair of primary veins, and two to four pairs of 

abmedial branches of second pair of primary veins; 

all lateral primary veins, secondary veins, and 

abmedial branches diverging at about 45° to their 

respective primary; angularly eucamptodromous; intersecondaries present; axillary bracing between midrib and first lateral primaries formed by tertiaries 

that are orthogonal to acute to midrib and orthogonal 

to laterals, and that form abmedially oriented 

chevrons; other intercostal tertiaries orthogonal, 

widely and irregularly spaced, forming a coarse reticulum; quaternaries orthogonal, forming a reticulum 

of three to five areas per tertiary area; quaternaries 

forming a quadrangular to pentagonal reticulum of 

areoles, about four to five areoles per fourth-order 

area; veinlets branching two or more times; typically 

at least two series of complete marginal loops; teeth 

entered medially to apically by veins of quaternary 

rank, flanked by weak accessory veins converging at 

apex of tooth (chloranthoid type).

Discussion. One of the most diagnostic features of Cercidiphyllum obtritum is the broad base 

that is typically truncate to shallowly cordate. The 

majority of the leaves have this type of base, are 

small, and have small teeth (pi. 3, figs. 5-8). A few 

specimens (pi. 3, figs. 1, 2) are larger and have 

suprabasal primaries and large teeth; these specimens 

may represent shade leaves. In the Paleocene to early 

Eocene C. genetrix (Newb.) Hick., the margin and 

venation are similar but the base is typically acute 

and the leaf shape flabellate (Hickey, 1977).

Cercidiphyllum genetrix and C. obtritum are 

morphologically similar and constitute a distinct 

(and extinct) type within the genus. Some undescribed leaves of Cercidiphyllum from the Fort 

Union Formation and from early Eocene rocks on 

the Similkameen River (USGS loc. 11015) have the 

strongly cordate base, orbicular shape, and crenate 

teeth similar to Oligocene and younger C. crenatum 

(Ung.) R.W. Br. and the extant C. japonicum S. and 

Z. Thus C. obtritum is unlikely to be ancestral to any 

of the Oligocene and younger species of 

Cercidiphyllum.

Hypotypes. UCMP 9270-9272 USNM 32681, 

32682; UW 31242-31244, 31285, 39711.

Occurrences. Localities 8428, 11018.

Family HAMAMELIDACEAE

Genus LANGERIA Wolfe and Wehr, n. gen.

Diagnosis. Leaves simple; venation pinnate; 

secondary veins mixed camptodromous to typically 

craspedodromous, broadly curving apically; intersecondary veins absent; tertiary veins orthogonal,

percurrent, alternate or opposite; axillary tertiary 

veins parallel to other intercostal tertiaries on one 

side of midrib but tending to be aparallel on other 

side (that is, axillary tertiaries are on second side 

formed by the merging of a tertiary vein orthogonal 

to midrib and a tertiary vein orthogonal to secondary); quaternaries branching, forming a coarse, irregular reticulum; in basal half of lamina, departure angle of secondary veins decreasing so that veins 

diverge from one another; in apical half of lamina, 

departure angle of secondary veins approximately 

constant; teeth numerous, compound, serration type 

C-3; sinuses rounded; teeth entered centrally by external secondary branches or by branches from loops 

of external secondary branches.

Type species. Langeria magnified Wolfe and 

Wehr.

Derivation of name. Susanne K. Langer was a 

major exponent and teacher of symbolic logic, which 

has had a major influence on the organization and 

analyses of scientific data. Both of us acknowledge 

the impact Mrs. Langer's writings have had on our 

work.

Langeria magnifica Wolfe and Wehr, n. sp. 

Plate 4, figures 1-4; plate 5, figures 1-4

Description. Leaves simple; shape elliptic to 

typically ovate, apex acute, base shallowly cordate to 

acute; petiole normal, as much as 6 cm long; margin 

serrate, apical angle acute, serration type C-2 or C-3, 

sinuses rounded, spacing regular, teeth simple to typically compound; venation pinnate; secondary veins 

10 to 12 pairs, departing basally at high (70° to 90°) 

angles that diminish apically, broadly curved, typically craspedodromous; third through fifth pairs of 

secondary veins diverging from one another, with 

three to six conspicuous, craspedodromous external 

secondary branches; intersecondary veins uncommon; tertiary veins spaced at about 0.3 to 0.5 cm, 

orthogonal, straight to slightly sinuous, simple or 

forked, percurrent; quaternary veins orthogonal, 

forming a coarse branched reticulum; quinternary 

veins orthogonal, forming a weakly branched reticulum of areoles; veinlets branching two to three times.

Discussion. The characters found in Langeria 

are characteristic of Hamamelidoideae, although not 

all characters are found in one extant genus. The high 

angle of divergence of the basal pairs of secondaries, the divergence from one another of the next 

two or three pairs (and the corresponding large number of external secondaries), and the curved sinuses 

are all indicative of the subfamilial assignment.

The specimen illustrated as plate 5, figures 2, 3, 

is probably an immature leaf. This is indicated by the 

close spacing of the tertiary veins and the small teeth.

Systematics 13
Langeria is one of the many Hamamelidoideae 

that occur in the Paleocene and Eocene of Western 

North America. "Fortunearid" weedi (Knowlt.) Wolfe 

is similar to L. magnified and may prove to be congeneric; "F." weedi has fewer secondary veins, fewer 

external secondary veins (and thus teeth), and the 

teeth are typically coarser than L. magnified.

Holotype. UW 39713; UCMP 9273 (counterpart).

Paratypes. UCMP 9274-9276; UW 31246, 

31286-31289.

Occurrence. Locality 8428.

Family PLATANACEAE

Genus MACGINITIEA Wolfe and Wehr, n. gen.

Diagnosis. Leaves simple; venation basally 

palinactinodromous; major veins extending to margin, each entering a lobe; some intersecondary veins; 

secondary veins numerous, smoothly and shallowly 

curving, but abruptly curving near margin and 

brochidodromous; tertiary veins percurrent, 

branched once or unbranched; quaternary veins 

forming a pronounced coarse reticulum; one series of 

marginal loops; axillary bracing between primary 

veins formed by secondary veins that depart from 

primaries at acute angles, curve, and merge to form a 

series of chevrons that point toward sinus; lamina 

lobed, sinuses between lobes curved.

Type species. Macginitiea gracilis (Lesquereux) Wolfe and Wehr [Liquidambar gracile].

Discussion. The placement of this type of leaf 

in Platanaceae was first clearly demonstrated by 

MacGinitie (1941), who referred them to Platanophyllum. The type species of Platanophyllum, 

P. virginiensis Font., is from the Albian of Virginia; 

although P. virginiensis is palinactinodromous, its 

clear relationship in Platanaceae has yet to be demonstrated. We prefer, therefore, to propose a new 

name for the Paleocene and Eocene leaves previously 

referred to Platanophyllum.

Both Brown (1962) and Hickey (1977) considered the "Platanophyllum" type of foliage to be referable to Platanus. The most obvious distinction between Platanus and Macginitiea is in the axillary 

bracing between the primary veins: in Macginitiea 

the bracing forms a series of conspicuous chevrons 

that point towards the sinuses, whereas in Platanus 

the bracing is formed (as in most actinodromous 

leaves) by veins that are orthogonal to their respective primaries, are straight, and join angularly. Further, the lamina on one side of the midrib is a virtual 

mirror image of the other side in Macginitiea, whereas the size of the lobes may vary greatly from one side 

to another in Platanus.

Most species of Macginitiea have lobes that 

lack teeth. If teeth are present, they are typically few 

and of uniform size. In Platanus, teeth are typically 

present and are of varying size on a given leaf. 

Whereas leaves of Platanus are typically suprabasally 

palinactinodromous, Macginitiea is basally palinactinodromous.

The leaves of Macginitiea, in comparison to 

Platanus, are regular in shape, margin, and venation. 

This could be interpreted as indicating a higher degree of specialization in Macginitiea than in 

Platanus.

Derivation of name. We take great pleasure in 

naming this genus for Harry D. MacGinitie. His 

work over a period of 50 years represents a major 

contribution to the paleobotany and paleoclimatology of the Tertiary of Western North America.

r

Macginitiea gracilis (Lesquereux) Wolfe and Wehr, n. comb.

Plate 6, figures 1-4

Liquidambar gracile Lesquereux, 1872, p. 287. 

Platanus dubia Lesquereux (non Ettingshausen),

1874, p. 406. 

Aralial gracilis Lesquereux, 1878, p. 236, pi. 39,

fig. 1. 

Aralia notata Lesquereux, 1878, p. 237, pi. 39, figs.

2-4. 

Aralia republicensis Brown, 1937, p. 183, pi. 55,

fig. 7. 

Platanus appendiculata auct. non Lesquereux. Berry,

1929, p. 249, pi. 52, fig. 5. 

Aralia whitneyi auct. non Lesquereux. Berry, 1929,

p. 260. 

Platanus nobilis auct. non Newberry. Brown, 1962

(part), p. 64, pi. 29, fig. 6. Hickey, 1977,

p. 131, pi. 31.

Discussion. As here conceived, the epithet 

gracilis is applied to leaves that (1) are typically five 

lobed, (2) have no teeth, (3) have broad lobes, and (4) 

have the veins that form the axillary chevrons approximately parallel to the brochidodromous secondary veins in the lobes. The types of Platanus nobilis 

are three lobed, are toothed, and the veins forming 

the axillary chevrons are typically not parallel to the 

brochidodromous secondary veins; these fossils represent a distinct species. The types of Aralia digitata 

are toothed and narrowly lobed; these represent a 

distinct species allied to the Eocene "Platanus" (or, 

more validly, Macginitiea) browni and "Platanus" 

wyomingensis.

In an unpublished manuscript, Brown transferred "Aralia" republicensis to Platanus. Brown 

(1937), however, did not furnish a description for 

"A." republicensis, and hence this epithet has not

14 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
been validly published. Arnold (1955) listed "Aralia 

republicensis" for the Princeton flora.

Hypotypes. UCMP 9277-9279; UW 39714, 

31247,31290.

Occurrences. Localities 8428, 11018.

Family FAGACEAE 

Genus FAGOPSIS Hollick

Fagopsis undulata (Knowlton) Wolfe and Wehr, n. comb.

Plate 7, figures 1-9

Fagus undulata Knowlton, 1899, p. 700, pi. 85, figs.

4,5. 

Carpinus grandis auct. non Unger. Dawson, 1890,

p. 87, text-fig. 21. 

Fagopsis longifolia auct. non (Lesquereux) Hollick.

Becker, 1961 (part), p. 59, pi. 16, figs. 9, 12.

Discussion. The rounded teeth and shallow sinuses distinguish this species from the sharper and 

more deeply incised teeth of the late Eocene Fagopsis 

longifolia (Lesq.) Roll. Fagopsis undulata also can 

have more numerous secondary veins and teeth than 

F. longifolia; in this character, F. undulata is more 

similar to the Paleocene F. groenlandica (Heer) 

Wolfe.

One character of leaves of all three known species of Fagopsis that ally them to Fagaceae rather 

than Betulaceae is that the serration type is Hickey's 

(1973) A-l and that the teeth are simple. In Betulaceae, the typical serration type is D-l to D-4 (some 

are A-3 or A-4) and each lamina invariably has some 

compound teeth. Also of major significance is the 

branch of the secondary vein that departs near the 

margin and ascends apically into the adjacent tooth 

(pi. 7, fig. 1); this architecture is of wide occurrence in 

extant Fagaceae.

The two specimens from the main Republic locality are both larger than the Resner Canyon and 

Graphite Creek specimens and have about 15 pairs of 

secondary veins in comparison to the 10 to 13 pairs 

on the specimens from the other localities. We do 

not, however, consider these differences to be of systematic value.

At both the Resner Canyon and Graphite Creek 

localities, leaves of Fagopsis undulata are accompanied by pistillate cones that are similar to those of 

F. longifolia described by MacGinitie (1953) from 

Florissant. The Republic cones, however, are not as 

large as those ofF. longifolia.

Lectotype. Specimen illustrated as pi. 85, 

fig. 5, by Knowlton (1899).

Hypotypes. \3CMP 9280-9282; USNM 

32683-32690; UW 39716.

Occurrences. Localities 8428, 11018, 11019.

Family BETULACEAE 

Genus ALNUS L.

Alnus parvifolia (Berry) Wolfe and Wehr, n. comb.

Plate 8, figures 1-8

Betula parvifolia Berry, 1926, p. 103, pi. 15, figs. 1-3.

Alnus elliptica Berry, 1929, p. 244, pi. 50, figs. 8-10.

Alnus cuprovallis Axelrod, 1966, p. 66, pi. 11, figs.

1-13. Wolfe, 1977, p. 58, p. 26, fig. 7;

text-fig. 11.

Carpinus grandis auct. non Unger. Berry, 1926 (part),

p. 104, pi. 15, figs. 4, 5.

Alnus corralina auct. non Lesquereux. Brown, 1937 

(part), p. 170, pi. 48, fig. 3.

Discussion. The abundant material from Republic indicates that the base of this Alnus ranges 

from shallowly cordate to acute; such variation is 

typical in many extant species of Alnus. In the acutebased specimens, the teeth are typically small, as in 

Berry's (1926) Joseph Creek specimens assigned by 

him to Carpinus grandis (?).

As noted by Wolfe (1977), this species belongs 

to the same group as the extant Alnus incana, of 

subgenus Alnus, although A. parvifolia has only a 

slight tendency for the teeth to be grouped. Axelrod 

(1966) compared A. cuprovallis to the extant A. crispa 

(Alt.) Pursh of subgenus Alnobetula, but A. parvifolia 

has none of the characters diagnostic of that group; 

Alnobetula does occur, however, in some Alaskan Eocene assemblages.

The associated cones (pi. 8, fig. 5) are tentatively assigned to Alnus parvifolia. The cones are the only 

type of Alnus cone and A. parvifolia is the only type 

of Alnus leaf at Republic.

Hypotypes. UCMP 9283-9285; USNM 32691, 

32692; UW 31253-31255, 31291,39721.

Occurrence. Locality 8428.

Genus BETULA L.

Betula leopoldae Wolfe and Wehr, n. sp.

Plate 9, figures 8-11

Description. Leaves simple; shape narrowly 

ovate, apex acuminate, base obtuse; margin serrate, 

apical angle acute, serration types typcially D-2 to 

D-4, sinuses angular, spacing regular, teeth compound with typically two subsidiary teeth on basal 

flank of major teeth; petiole normal, 0.8 cm long; 

venation pinnate; about 12 pairs of secondary veins, 

departing at a 45° angle, straight, craspedodromous, 

entering teeth centrally in basal and medial parts of 

lamina and entering teeth basally in apical part then 

bending sharply toward apex; typically two external 

secondary veins per secondary, craspedodromous; intersecondary veins absent; tertiary veins spaced 

about 0.8 cm apart, percurrent, opposite or alternate,

Systematics 15
slightly convex; quaternaries forming an irregularly 

polygonal mesh; quinternaries forming irregularly 

polygonal areoles; veinlets stout, branching once or 

twice.

Discussion. The sharp apical bend of the apical secondary veins on entering the teeth (pi. 9, fig. 8) 

is indicative of Betula, Carpinus, or Ostrya. Both 

Carpinus and Ostrya have typically large, quadrangular areoles, most of which have no veinlets. In extant 

Betula, as in the fossils (pi. 9, fig. 10), the areoles are 

small and have branching veinlets.

No other described Betula leaves from the Tertiary of Western North America are highly similar to 

B. leopoldae. The other described species are either 

more finely serrate than B. leopoldae or they have 

fewer secondary veins (as in the B. papyrifera complex). Leaves of B. leopoldae are present in the U.S. 

Geological Survey's collection from Princeton, British Columbia.

Holotype. UVJ 39722; UCMP 9286 (counterpart).

Paratype. UW 31256.

Occurrence. Locality 8428.

Family MYRICACEAE

Genus COMPTONIA L'Heritier

Comptonia columbiana Dawson

Plate 9, figures 1-3

Comptonia columbiana Dawson, 1890, p. 81,

text-fig. 10. 

Comptonia hesperia auct. non Berry. Brown, 1937

(part), p. 169, pi. 46, figs. 12-14. 

Myrica (Comptonia) cuspidata auct. non Lesquereux.

Dawson, 1890, p. 80, text-fig. 9.

Discussion. The Republic specimens are 

doubly serrate and compare well to Dawson's (1890) 

illustration of Comptonia columbiana. The Republic 

material also represents a simple leaf, and thus cannot represent the leaflet of the somewhat similar Lyonothamnus. The doubly serrate foliage of C. columbiana is unique in the genus; all other described fossil 

species and the one extant species are singly serrate.

Hypotypes. UCMP 9287-9289; USNM 32693, 

32694; UW 39723.

Occurrences. Localities 8428, 11018, 11019.

Family THEACEAE

Genus TERNSTROEMITES Berry

Ternstroemites sp. "A" 

Plate 9, figures 4-7

Discussion. Two narrowly elliptic leaves have 

small closely appressed teeth that are furnished with 

small triangular glands (probably setae). The intercostal areas are of irregular size and shape, the

secondary veins are festooned brochidodromous, and 

the tertiary veins are irregularly spaced but tend to be 

percurrent. Tertiary veins that have a similar pattern 

occur, for example, in Gordonia; as well, Gordonia 

tends to have curved secondary veins, which closely 

approach the margin before looping (as in the fossils). 

These fossil leaves thus represent a theaceous taxon, 

but the limited material and its lack of preservation 

of the higher vein orders does not warrant naming.

Specimens. UCMP 9290; UW 31259, 39724.

Occurrence. Locality 8428.

Ternstroemites sp. "B"

Plate 10, figures 1-4,6

Discussion. These leaves share two significant 

sets of characters with the preceding taxon: low 

rank secondary venation that is festooned 

brochidodromous and the small, closely appressed 

teeth that have apparent setae. Thus, these leaves 

also represent Theaceae, but they differ from Ternstroemites "A" in their elliptic shape, higher angle of 

departure of the secondary veins, and lower rank 

(more irregular) tertiary vein system. The irregularity 

of the tertiary vein system and the distance from the 

margin at which the secondary veins loop is most 

similar to Cleyera, a small genus that is dominantly 

New World but with one species in Asia. As with 

T. "A", we consider the current material to be insufficient for naming.

Specimens. UW 31292, 31293, 39719.

Occurrence. Locality 8428.

Family TILIACEAE 

Genus TILIA L.

Tilia johnsoni Wolfe and Wehr, n. sp.

Plate 10, figures 5, 7

Description. Leaf simple; venation perfectly 

and basally actinodromous, three pairs of lateral primary veins; lamina symmetrical, shape orbiculate, 

apex acuminate, base cordate; margin serrate to dentate, serration type A-3 to C-3, sinuses curved to 

broadly angular, spacing regular, first pair of lateral 

primary veins parallel to medial secondary veins, 

broadly curving, giving off three external craspedodromous branches that are parallel to next pair 

of lateral primaries; four pairs of medial secondary 

veins, shallowly curving, craspedodromous, forking 

and giving off one or two external branches that may 

also fork; tertiary veins orthogonal, closely and uniformly spaced, most percurrent; quaternary venation 

orthogonal, forming a quadrangular to pentagonal reticulum; higher order venation obscure.

Discussion. The few pairs of medial secondary 

veins and the equidistant extension towards the apex 

of both the first lateral primary veins are indicative of

16 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
section Anastraea and particularly subsection Reticulares. This section was considered to have the least 

specialized floral morphology in Tilia (Engler, 1909).

Tilia johnsoni represents the oldest valid 

megafossil record of the genus. Pollen referable to 

Tilia first appears near the Paleocene-Eocene boundary (E. B. Leopold, oral commun., 1982), and Reid 

and Chandler (1933) have described a fruit from the 

early Eocene as Eotilia. The first pollen of Tilia is in 

assemblages that are mesothermal, and Eotilia is in a 

megathermal assemblage. Indeed Tiliaceae are, except for Tilia, exclusively megathermal to mesothermal, and presumably Tilia, which is both mesothermal and microthermal, evolved from some 

mesothermal genus. What is of interest is that in less 

than 10 million years after Tilia first appeared in the 

palynological record, well-defined foliage is found in 

a microthermal assemblage.

We take pleasure in naming this species for 

Kirk Johnson, who has assisted in collecting much of 

the new material from Republic.

Holotype. UW 39712; UCMP 9291 (counterpart).

Occurrence. Locality 8428.

Family ITEACEAE 

Genus ITEA L.

Itea sp.

Plate 11, figures 1-3

Discussion. Three fragments all representing foliar apices have the characters diagnostic of 

Itea: ( 1) strongly eucamptodromous, strongly curving 

secondary veins, (2) somewhat sinuous tertiary veins 

that are all approximately perpendicular to the midrib, and (3) a finely serrate margin that has teeth that 

are uniformly spaced and markedly point apically.

Today Itea is an east Asian/east American vicariant, with about 10 species in east Asia and 1 in 

the Eastern United States. The genus is primarily 

mesothermal, although a few species extend into 

microthermal climates. This is the oldest known, as 

well as the first American, record of the genus as a 

fossil.

Specimens. UW 31262, 39725.

Occurrence. Locality 8428.

Family ROSACEAE 

Genus PHOTINIA Lindley

Photinia pageae Wolfe and Wehr, n. sp.

Plate 11, figures 4-6

Description. Leaf simple; lamina symmetrical, 

shape narrowly ovate to elliptic, apex acuminate, 

base symmetrically decurrent to cuneate; margin serrate, apical angle acute, serration type B-l to B-2, 

sinuses narrowly rounded to acute, spacing regular;

teeth of very unequal size but not compound, about 

two per secondary vein; petiole normal; venation pinnate; secondary veins brochidodromous departing at 

an angle of about 70°, straight to somewhat zigzag, 

some aparallel, forming intercostal areas of somewhat differing size and shape, looping angularly close 

to margin, giving off craspedodromous external 

branches that enter teeth centrally; intersecondary 

veins common and conspicuous; tertiary veins at 

acute angles to secondary veins, forming a random 

reticulation; quaternary veins randomly reticulate; 

quinternary veins randomly reticulate, forming areoles; veinlets irregularly ramified.

Discussion. The acutely angled and irregularly 

and conspicuously random third-order reticulum, irregular intercostal areas, and serration type place 

these leaves in Photinia (s.s., excluding Heteromeles).

Photinia pageae is both the oldest and first 

American occurrence of the genus as a fossil. Photinia is typically mesothermal and is primarily in the 

Notophyllous Broadleaved Evergreen forest in both 

Central America and eastern Asia, although some 

species extend into microthermal climates in Asia.

We take pleasure in naming this species in recognition of Virginia M. Page's contributions to Cretaceous and Tertiary xylotomy.

Holotype. UW39188.

Paratypes. UCMP 9292; UW 39195.

Occurrence. Locality 8428.

Family ANACARDIACEAE 

Genus RHUS L.

Rhus malloryi Wolfe and Wehr, n. sp.

Plate 12, figures 1,2, 6, 7, 12

Dipteronia americana Brown, 1935 (part, nontypic), 

p. 580, pi. 67, fig. 12.

Description. Leaflets symmetrical but base 

asymmetrical; shape narrowly elliptic to lanceolate, 

apex acute, base acute; margin serrate, apical angle 

acute, serration type A-1; sinuses acute, spacing regular; teeth simple, one per secondary vein; short petiolule; venation pinnate; secondary veins gradually 

curved, craspedodromous to semicraspedodromous, 

entering teeth centrally or ending in sinuses, some 

bifurcating and sending the apical branch to next 

most apical tooth; some weak intersecondary veins; 

external secondary branches forming loops that thin 

abmedially; tertiary veins orthogonal to acute, tending to thin midway between secondary veins; higher 

orders of venation indistinct.

Discussion. The tendency to thinning of the 

tertiary veins and the loops of the external secondary 

veins is diagnostic of Anacardiaceae. The serrate 

margin and variable behavior of the secondary veins 

are, moreover, indicative of Rhus (s.s.).

Systematics 17
The early Eocene Rhus mixta (Lesq.) MacG. is 

more linear than R. malloryi, has stronger secondary 

veins, and has longer and more conspicuous intersecondary veins.

We take pleasure in naming this species for 

V. S. Mallory, who, as chairman of the Geology and 

Paleontology Division of the Burke Memorial Museum, has encouraged the present study.

Holotype. UW391\8.

Paratypes. UCMP 9293, 9294; UW 31270, 

31294,31295.

Occurrence. Locality 8428.

Family BURSERACEAE

Genus BARGHOORNIA Wolfe and Wehr, n. gen.

Diagnosis. Leaves presumed pinnate; leaflets 

asymmetrical; venation pinnate; margin serrate, teeth 

irregularly spaced, simple; secondary veins pronouncedly and sharply curving near margin, 

semicraspedodromous; tertiary venation forming a 

coarse, irregular reticulum; sinuses supplied with 

veins originating on abmedial sides of secondary vein 

loops and from craspedodromous external secondary 

veins.

Type species. Barghoornia oblongifolia Wolfe 

and Wehr.

Discussion. See under B. oblongifolia.

Derivation of name. In recognition of his multitudinous contributions to paleobotany Precambrian through Quaternary we name this genus for 

the late Elso S. Barghoorn.

Barghoornia oblongifolia Wolfe and Wehr, n. sp.

Plate 12, figures 3-5

Description. Leaflets asymmetrical; shape narrow oblong, apex acute, base acute; long-petiolulate; 

margin coarsely serrate, apical angle acute, serration 

type A-4 to D-4, sinuses angular, spacing irregular; 

about two teeth per secondary vein, simple; petiolule 

about 7 mm long; venation pinnate; eight pairs of 

secondary veins, lowest pair departing at 70°, other 

pairs at 80°, straight, looping sharply near margin to 

make an almost quadrangular intercostal area, 

semicraspedodromous; external secondary branches 

entering teeth typically centrally but some apically; 

tertiary veins orthogonal, few forming a large irregularly polygonal reticulum; quaternary veins orthogonal, forming a quadrangular to pentagonal reticulum.

Discussion. The single specimen (and its 

counterpart) has pronounced asymmetry, both at the 

base and in the medial part of the lamina; this is a 

strong indication of a leaflet of a pinnately compound 

leaf. The strong veins terminating in the sinuses, as 

well as the probable pinnately compound organization, are indicative of Rosidae.

Among pinnately compound Rosidae, the Republic leaflet is unique. Particularly peculiar is the 

consistently semicraspedodromous venation. In 

toothed, pinnately compound Rosidae, semicraspedodromy is found in only one family, Burseraceae; 

indeed, five genera of Burseraceae have semicraspedodromous venation consistently present in some 

species. The tertiary venation of the fossil, however, 

is most similar to that of the craspedodromous Bursera, which has broad A-l (almost crenate) serrations. Some Burseraceae also have long petiolules. All 

major characters of Barghoornia occur in Burseraceae, and we thus consider the familial assignment 

secure.

Holotype. USNM 32695A, B.

Occurrence. Locality 8428.

Family ACERACEAE 

Genus ACER L.

"Acer" arcticum Heer

Plate 12, figures 11, 16

Acer arcticum Heer, 1876 (part), p. 86, pi. 22, figs. 1, 

3-7; pi. 23, figs. 1-9; pi. 24, figs. 1-3.

Discussion. The Republic leaves have the 

shallow lobes and rounded teeth that characterize 

Heer's material from the early Eocene of Spitzbergen. 

The validity of the generic reference, however, is 

problematic.

Almost all Eocene leaves of Acer have axillary 

bracing of the type shown in plate 12, figure 11: the 

tertiary veins join a vein midway between the primary and secondary veins and this vein thins as it 

approaches the axil. Such venation is not found in 

any extant species of Acer but is found in other families of Sapindales and particularly in Rutales. This 

type of axillary bracing in Eocene Acer could thus be 

considered to represent the retention of a primitive 

character.

The rounded teeth of "'Acer" arcticum are not 

found in any extant species of Acer, and we are thus 

not totally convinced that these leaves represent Acer. 

That these leaves have a large number of characters 

in common with Acer is also certain. A strong resemblance is also evident between "A" arcticum and 

"Ampelopsis" acerifolia Newb. from the Paleocene 

and early Eocene (Hickey, 1977); other than overall 

architecture, the similarities include the rounded 

(some are emarginate in "Ampelopsis" acerifolia) 

teeth and tendency for the tertiary veins to form a 

V-shaped pattern pointing apically.

No samaras of valid Acer have been found with 

"Ampelopsis" acerifolia; commonly, however, these 

leaves occur with a samara of apparent sapindaceous 

affinity (Wing, 1981). These samaras were attached 

the opposite of Acer: the strongly veined "back" of

18 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
the samara was medial rather than marginal as in 

Acer. These apparent sapindaceous seeds have not 

been found attached to one another, so it is unknown 

whether they were borne in threes as in Sapindaceae. 

The same type of sapindaceous samara also occurs 

with the leaves of "Acer" arcticum at Republic. If the 

sapindaceous samaras (and not the Acer samaras reported below) are the seeds of°"Acer" arcticum then 

some interpretations are as follows:

1. "Acer" arcticum and "Ampelopsis" acerifolia represent an extinct genus of Sapindaceae. Arguing 

against this interpretation is that actinodromy 

does not occur in extant Sapindaceae.

2. "Acer" arcticum and "Ampelopsis" acerifolia represent an extinct genus and family of Sapindales. 

This interpretation would be particularly attractive if the seeds were borne in threes as in 

Sapindaceae; this extinct family would be a sister 

group of Aceraceae.

3. "Acer" arcticum and "Ampelopsis" acerifolia represent an extinct genus of Aceraceae. This interpretation would be supported if the seeds were 

borne in twos.

We think that "Acer" arcticum and "Ampelopsis" acerifolia are closely related. The fact that no 

Acer samaras have been found associated with "Ampelopsis" acerifolia strongly argues against either Ampelopsis acerifolia or "Acer" arcticum being members 

of Acer. We thus suggest that either interpretation 2 

or 3 will prove to be valid.

Hypotypes. VCMP 9295; UW 39726 (counterpart).

Occurrence. Locality 8428".

Acer sp.

Plate 12, figures 9, 13-15

Discussion. These samaras vary in the shape 

of the wing but all have the same angle between the 

distal side of the samara and line of dehiscence. The 

seed itself was inflated. The closest similarities are to 

seeds of section Macrantha.

Specimens. UCMP 9296, 9297; USNM 

32696; UW 31272, 39728, 39191.

Occurrences. Localities 8428, 11018.

Family SAPINDACEAE

Genus BOHLENIA Wolfe and Wehr, n. gen.

Diagnosis. Leaves apparently pinnately compound; leaflets with serrate margin, serration type 

A-l, teeth compound or simple; venation pinnate; 

secondary veins with uniform angle of departure, alternate pairs of secondary veins craspedodromous, 

entering teeth centrally; other pairs of secondary 

veins bifurcating just before reaching sinuses between major teeth, apical branch extending parallel

to basal side of lobe immediately apical, basal branch 

extending parallel to apical side of major tooth immediately basal; tertiary veins acute to secondary 

veins, straight to curved and merging midway between secondaries.

Fruit, a three-parted samara; pedunculate; samaras joined for about half the proximal margin 

along a vascularized stalk, vascularization extending 

across samara to a centrally located seed; samara fully enclosing seed; distal side of samara forming threefourths of a circle; samara vascularized by a reticulum of veins that branch at acute angles.

Type species. Bohlenia americana (Brown) 

Wolfe and Wehr [Dipteronia americana Brown].

Discussion. See under Bohlenia americana.

Derivation of name. This genus is named for 

Anne Bohlen of Portland, Oreg. Miss Bohlen is an 

inspiring teacher in biology, as evidenced by her being named Oregon's High School Biology Teacher of 

the Year. She was also instrumental in guiding and 

encouraging the senior author's early training.

Bohlenia americana (Brown) Wolfe and Wehr, n. comb.

Plate 13, figures 1-8

Dipteronia americana Brown, 1935 (part), p. 580, pi.

67, fig. 6. 

Comptonia insignis auct. non Lesquereux. Berry,

1929, p. 241, pi. 50, fig. 5.

Supplementary description. Leaf pinnately 

compound; leaflets ovate symmetrical, base obtusely 

asymmetrical, apex acute to acuminate; margin serrate, lobed, apical angle acute, serration type A-l; 

lobes typically with two teeth on basal side; venation 

pinnate; about eight pairs of secondary veins, angle 

of departure uniformly about 50°; alternate pairs of 

secondary veins craspedodromous, broadly curving, 

entering lobes centrally; other secondary veins bifurcating just before reaching sinuses between lobes, apical branch extending parallel to basal side of lobe 

immediately apical, basal branch extending parallel 

to apical side of lobe immediately basal; tertiary 

veins straight to curved and merging midway between secondaries, originations on secondaries acute; 

higher order venation obscure.

Discussion. The leaflet illustrated by Brown 

(1935) as Dipteronia americana represents Rhus malloryi and is thus excluded from this discussion. 

Brown, however, also included in D. americana the 

two leaflets assigned by Berry (1929) to Comptonia 

insignis. These leaflets apparently represent, from 

their position on the matrix, part of the same leaf. 

Brown (1935) did not designate a holotype, and thus 

we choose as the lectotype the two leaflets illustrated 

by Berry.

Systematics 19
The lectotype of "Dipteronia" americana has 

large teeth that have one or two subsidiary teeth on 

their basal flanks, and pairs of craspedodromous 

secondary veins that alternate with pairs of secondary veins that prominently bifurcate just before 

reaching the sinuses. This bifurcation does not occur 

in Dipteronia, in which the sinuses are connected to 

the secondary veins by an external secondary vein. 

The tertiary veins are orthogonal in Dipteronia.

Bifurcating secondary veins similar to those of 

Bohlenia americana occur in members of 

Sapindaceae, particularly in Cardiospermum and 

Serjania; both genera are members of Eupaullinieae. 

In species of these extant genera, however, the 

secondary vein typically forks at the sinus, or, if forking before reaching the sinus, the basal branch is 

weak and extends to the sinus before passing into the 

tooth. We therefore consider the Republic leaflets to 

represent an extinct genus.

That the fruits here assigned to Bohlenia americana represent Sapindaceae is indicated by the one 

specimen (pi. 13, figs. 4-6) that demonstrates that the 

samaras were borne in threes (samaras in Aceraceae 

are borne in twos). In Dipteronia, moreover, the samaras are typically not fused to one another (or for 

only a short distance) and the vascular strand extends 

from the peduncle straight to the seed.

Fruits of four of the five genera of Eupaullinieae 

and of the sole genus of Thinouieae (these two subtribes comprise the Paullinieae) analyzed indicate 

some basic similarities to fruits of Bohlenia, other 

than the trilocular condition basic to Sapindaceae. In 

our analysis we assume that the distal branching of 

the placental axis in Bohlenia is advanced and that 

the ancestor of Bohlenia would have had the seeds 

borne proximally. Refusion of the placental branches 

would probably produce apically borne seeds; the position of the seeds in Bohlenia is fundamentally apical the branches are at the apical end of the central 

axis. Thus, Bohlenia is most similar to Serjania 

(fig. 5) in having apically borne seeds and a samara. 

The venation in the samara of Bohlenia is formed of 

acutely branching and typically open veins (pi. 13, 

fig. 2); this is similar to Serjania and Thinouia. In 

Cardiospermum and Urvillea, the venation is closed, 

forming a reticulum. In Cardiospermum, the fruit is 

an inflated capsule and the seeds are borne midway 

along the central axis; this last feature is shared with 

Urvillea, which, however, has a much less inflated 

capsule than Cardiospermum. In Thinouia, the seeds 

are borne basally and the wing is apical. Paullinia has 

a decidely sclerified fruit. The morphology of the 

fruits here assigned to Bohlenia is indicative of a 

relationship to Serjania.

The association of the leaflets and samaras of 

Bohlenia americana at Republic is not in itself sufficient grounds for the inclusion of both organs in the 

same taxon. We consider, however, the association at 

Florissant to be strongly indicative that the types of 

leaflet and samara here named Bohlenia represent the 

same genus; MacGinitie (1953) noted that the leaflets 

and samaras of "Dipteronia" insignis (= Bohlenia insignis) occur in association at all Florissant localities. 

The Republic occurrence represents the association 

of the same type of leaflet and samara (although specifically distinct from the Florrissant taxon). Yet a 

third such association occurs in the Joseph Creek 

flora; Berry (1926) assigned a leaflet of Bohlenia morphology to Myrica uglowi, and "Dipteronia" 

( Bohlenia) samaras are present in later collections 

from the Joseph Creek locality housed in the Geological Survey of Canada's collections in Ottawa. We 

think that all these joint occurrences of leaflets and 

samaras are sufficient grounds for the inclusion of 

both organs in the same genus.

Figure 5. Fruits of Sapindaceae. A, Serjania. B, Cardiospermum. C, Urvillea. D, Urvillea (diagrammatic representation of cross section, after Radlkofer, 1933). E, Thinouia. 

Ff Bohlenia. G, Bohlenia (diagrammatic interpretation of 

cross section).

20 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
The Paullinieae are today basically neotropical, 

with two genera (Lophostigma and Urvillea) endemic 

to South America. Also of interest is that Paullinieae 

were considered by Radlkofer (1933) to be the least 

advanced extant Sapindaceae (and Serjania the least 

advanced of Eupaullinieae). Although the present 

distribution could be interpreted as indicating a 

South American origin for the family, the occurrence 

of Bohlenia, which was probably derived from a 

Serjania-\ike ancestor, strongly indicates the possibility of a boreotropical origin and diversification for 

the family.

Lectotype. USNM 38094.

Hypotypes. UCMP 9298-9300; UW 31278, 

31298,39192,39729.

Occurrences. Localities 8428, 11018.

Genus KOELREUTERIA Laxmann 

Koelreuteria arnoldi Becker

Plate 12, figures 8, 10

Koelreuteria arnoldi Becker, 1961 (part), p. 83, pi. 27, 

figs. 1-4.

Discussion. In their small size and pattern of 

wing venation, the Republic fossils are similar to the 

Ruby types of Koelreuteria arnoldi Beck. The holotype contains three seeds, but none of the four Republic specimens shows the presence of seeds within 

the capsule. As noted by Becker, the capsules of 

K. arnoldi appear to have been almost flat, unlike the 

inflated capsules of extant Koelreuteria.

Hypotypes. UCMP 9301; UW 39189, 39190.

Occurrence. Locality 8428.

Family CORNACEAE 

Genus CORNUS L.

Cornus sp.

Plate 14, figures 1-4

Discussion. The strongly and apically arched 

eucamptodromous secondary veins and widely 

spaced tertiary veins oriented perpendicular to the 

midrib indicate that these fragmentary leaves represent Cornus. The margins of the fossils are slightly 

erose as in Cornus.

Although the generic assignment seems certain, 

the limited material does not warrant naming. The 

Republic specimens do not appear assignable to any 

previously described species from the North American Tertiary.

Specimens. UW 31276, 39193, 39734.

Occurrence. Locality 8428.

Family DAVIDIACEAE

Genus TSUKADA Wolfe and Wehr, n. gen.

Diagnosis. Leaves simple; venation pinnate; 

secondary veins craspedodromous, broadly curving

apically; intersecondary veins absent; tertiary veins 

acute to secondary veins (AO pattern), some 

branched; axillary tertiary veins tending to be parallel 

to other intercostal tertiaries; quaternaries branching, 

forming a coarse, dominantly quadrangular reticulum; three most basal pairs of secondary veins crowded near base, giving an almost actinodromous appearance; external secondary veins more numerous 

on three most basal pairs of secondary veins than on 

more apical pairs; external secondary veins craspedodromous to camptodromous; teeth entered medially and with lateral bracing veins that loop; weakly 

developed sinal knot; teeth at least one per secondary 

vein; serration type broadly A-l; ill-defined glandular area on apex of teeth.

Type species. Tsukada davidiifolia Wolfe and 

Wehr.

Derivation of name. We take pleasure in naming this genus for Matsuo Tsukada in recognition of 

his extensive work in Quaternary paleoecology and 

biogeography.

Tsukada davidiifolia Wolfe and Wehr

Plate 14, figures 5, 6; plate 15, figures 1-4

Description. Leaf simple; shape symmetrical 

wide elliptic, apex acuminate, base narrowly and 

shallowly cordate; margin typically serrate (a few 

teeth dentate), apical angle acute, spacing regular, 

teeth simple; petiole normal; venation pinnate; 

secondary veins six pairs, (except for basal pair) departing at an angle of 45°, broadly curving, craspedodromous, entering teeth centrally, giving off one 

craspedodromous or camptodromous external 

branch except for most basal of the six pairs, which 

has seven external branches; most basal pair of 

secondary veins weak, departing at an angle 80°, 

broadly curving, semicraspedodromous; tertiary 

veins orthogonal, percurrent, alternate or opposite, 

uniformly spaced; higher vein orders indistinct.

Discussion. The serration type, slightly cordate base, broadly curving and craspedodromous 

secondary veins, and crowded basal secondary veins 

are characters that are combined in the extant 

Davidia involucrata S. and Z., which is the sole extant 

member of Davidiaceae. In contrast' to Davidia 

leaves, however, the leaves of Tsukada have an AO 

(rather than an RR) tertiary vein orientation, they 

have a weakly developed sinal knot, and they also 

differ in details of dental morphology and venation. 

In Davidia, the lateral bracing veins are strong and 

typically approximately straight, the external secondary branches are consistently craspedodromous, and 

the dental apices have a clearly defined and elongated 

gland; in Tsukada, the lateral bracing veins form disSystematics 21
tinct loops, the external secondary branches can be 

camptodromous (as well as craspedodromous), and 

the dental apices have a poorly developed and short 

gland.

Tsukada, in some characters, is morphologically intermediate between Davidia and some members 

of Escalloniaceae. The AO tertiary vein orientation, 

weak sinal knot, narrowly rounded teeth, and presence of some camptodromous external secondary 

branches of Tsukada are characters that are found in 

some Escalloniaceae but are absent in Davidia. If 

Tsukada represent a low grade of foliar morphology 

in Davidiaceae, then Davidiaceae are closely related 

to Escalloniaceae but not to Cornaceae (and should 

thus be excluded from Cornales).

Holotype. UW71095.

Paratypes. \W 39187, 71081; UCMP 9302 

(counterpart of UW39187).

Occurrence. Locality 8428.

Family OLACACEAE 

Genus SCHOEPFIA Schreber

Schoepfia republicensis (LaMotte) Wolfe and Wehr, n. comb.

Plate 16, figures 1-3

Cornus acuminata Berry, 1929, p. 260, pi. 59, fig. 3. 

Cornus republicensis LaMotte, 1944, U.S. Geol. Survey Bull. 924, p. 126.

Discussion. Berry's (1929) original specimen 

lacks a base but has the pronounced acrodromy of the 

two specimens illustrated here. In Cornus, acrodromous veins depart from the midrib about halfway the 

distance to the apex and are typically the fourth pair 

of secondary veins, in contrast to the Republic specimens in which the acrodromous veins depart near the 

base and are the second pair of secondary veins.

A tendency for acrodromous secondary veins 

and tertiary veins oriented perpendicular to the midrib is evidenced in Olacaceae, particularly in Anacalosa and even more pronounced in Schoepfia. One 

critical character is the decurrency of the lamina to 

form an alate petiole; two pairs of veins one weak 

pair and the most basal pair of secondary 

veins depart from the midrib along the petiole and 

extend along the wing to flare out in the lamina. This 

characteristic architecture is totally lacking in Cornus 

but is found in Schoepfia.

Olacaceae are predominantly megathermal with 

some mesothermal representatives, among which is 

Schoepfia. Acrodromy is more pronounced in the extant American than in the extant Asian species of 

Schoepfia, and thus S. republicensis is apparently 

most closely related to the extant American species. 

The pollen type referred to as Anacalosidites includes 

the morphology of Schoepfia, and this pollen type is 

known in mesothermal Eocene assemblages in North

America (Leopold in MacGinitie, 1974) to marginally microthermal Miocene assemblages (Wolfe, 1962).

The epithet "acuminata" was preoccupied in 

Cornus, as recognized by LaMotte (1944), who proposed the epithet Republicensis.

Hypotypes. USNM 32683; UW 39194.

Occurrence. Locality 8428.

INCERTAE SEDIS (HAMAMELIDIDAE?) 

Genus REPUBLICA Wolfe and Wehr, n. gen.

Diagnosis. Leaves simple; shape symmetrical; 

margin entire; venation pinnate; secondary veins several, irregularly spaced, departure angle high on most 

basal pair (which are also weak), departure angle low 

on medial pairs and gradually increasing toward 

apex, broadly curving in basal and medial parts of 

lamina and narrowly curving in apical part, eucamptodromous, extending to margin before looping; 

conspicuous external secondary veins in basal half of 

lamina, departing at acute angles and forming a series of ladderlike loops; more apical intercostal areas 

conspicuously narrowing toward margin; intersecondary vein typically absent; tertiary veins orthogonal, 

percurrent, or branched; axillary tertiary bracing orthogonal; quaternary veins orthogonal, branched, 

forming a conspicuous reticulum.

Type species. Republica hickeyi Wolfe and 

Wehr.

Derivation of name. For Republic, Wash.

Republica hickeyi Wolfe and Wehr, n. sp.

Plate 16, figures 4, 5

Description. Leaf simple; shape symmetrical, 

wide elliptic, apex broadly acute, base acute; margin 

entire; texture coriaceous; petiole thick; venation pinnate, midrib thick at base, thinning markedly toward 

apex, straight; secondary veins eight on one side, nine 

on other; two most basal pairs of secondary veins 

departing at angle of 50°, somewhat irregular and 

weak, eucamptodromous; more apical secondary 

veins departing at angles of 45° to 55° (increasing 

apically), broadly (basally) to narrowly (apically) 

curving, eucamptodromous at the margin; a single 

series of conspicuous external secondary loops in basal two-thirds of lamina, formed by external branches 

that typically depart at low (about 30°) angles and 

that loop at margin to create a ladderlike effect; more 

apical intercostal areas conspicuously narrowing 

towards margin; intersecondary veins typically absent; tertiary veins uniformly spaced, orthogonal, 

percurrent or branched; axillary tertiary bracing orthogonal; quaternary veins orthogonal, branched, 

forming a quadrangular to pentagonal reticulum;

22 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
quinternary veins randomly reticulate forming areoles; veinlets typically once-branched.

Discussion. The affinities of this wellpreserved, highly coriaceous (and thus almost certainly evergreen) leaf are not certain. The absence of 

weak lateral veins at the laminar base excludes 

Lauraceae, despite the superficial resemblance to 

some species of Lauraceae. Some evergreen Central 

American species of Clethra also have a superficial 

resemblance, but these do not have the many external 

secondary branches in the medial and few or none in 

the apical parts of the lamina.

Republica has several points of resemblance to 

the ulmaceous Girroniera. Leaves of this extant genus 

typically lack strong external secondary veins (although a few occur in some leaves); if an external 

secondary vein is present, the angle of departure is 

acute as in Republica, but the loops formed apical to 

this external vein are bounded basally and apically by 

veins that are perpendicular to the midrib. In all other architectural features, however, Republica and Girroniera are similar. If strong and numerous external 

secondary veins were known in genera closely allied 

to Girroniera, we would not hesitate to assign Republica to Ulmaceae. The pattern of strong, numerous 

external secondary veins is common in Hamamelididae, and we suggest that Republica hickeyi is almost certainly related to the leaves (1) originally 

called Laurophyllum litseafolia MacG., which were 

transferred to Artocarpoides (Wolfe, 1968) and finally 

to Dicotylophyllum (Wolfe, 1977) and (2) of D. kummerensis (Wolfe) Wolfe. Republica hickeyi can be 

readily distinguished from these other two species by 

the external secondary loops that extend to the margin; in the other species a second small series of loops 

is present between a given major external secondary 

loop and the margin.

The specific epithet honors Leo J. Hickey's contributions to the comparative foliar morphology of 

the angiosperms, both fossil and extant.

Holotype. USNM 32697A, B.

Occurrence. Locality 8428.

SYSTEMATIC CHANGES IN OTHER EOCENE 

FLORAS

Sassafras ashleyi Axelrod

Sassafras ashleyi Axelrod, 1966, p. 70, pi. 15, figs.

1-9. 

Sassafras hesperia auct. non Berry. Brown, 1937

(part), p. 174, pi. 53, fig. 10. MacGinitie 1953,

p. 113, pi. 35, fig. 1. 

Discussion. See under Sassafras hesperia.

Bohlenia insignis (Lesquereux) Wolfe and Wehr, n. comb.

Myrica insignis Lesquereux 1878, p. 135, pi. 65, figs.

7,8. 

Dipteronia insignis (Lesquereux) Brown, 1937,

p. 181, pi. 59, figs. 10-12. MacGinitie, 1953,

p. 142, pi. 58, figs. 3, 6; pi. 72, fig. 5. 

Myrica uglowi Berry, 1926, p. 100, pi. 18, fig. 1.

Discussion. The leaflets of "Dipteronia" insignis have pairs of craspedodromous secondary 

veins that alternate with pairs of conspicuously bifurcating secondary veins; these leaflets thus conform to 

Bohlenia. The leaflets of B. insignis are, however, 

simply serrate and have more convex teeth than 

B. americana. The samaras assigned to "Dipteronid" 

insignis are also similar to those of B. americana in 

having an attachment scar about half the length of 

the proximal side, along which extends the vascular 

supply for the seed.

We are uncertain as to whether the Ruby 

"Dipteronia" insignis (Becker, 1961) is valid or represents Bohlenia americana; the illustrations are insufficient. The Bridge Creek "Dipteronia" (Brown, 1959) 

also represents Bohlenia, but the size of the samara is 

larger than any specimen of either B. americana or 

B. insignis. The Bridge Creek leaflet assigned to 

Dipteronia (Brown, 1940) is poorly preserved but appears to represent Rhus.

Republica kummerensis (Wolfe) Wolfe and Wehr, n. comb.

Artocarpoides kummerensis Wolfe, 1968, p. 19, pi. 4,

figs. 1, 7, text-fig. 12. 

Dicotylophyllum kummerensis (Wolfe) Wolfe, 1977,

p. 86, pi. 25, fig. 7; pi. 30, fig. 11.

Discussion. see p. 23

Republica litseafolia (MacGinitie) Wolfe and Wehr, n. comb.

Laurophyllum litseafolia MacGinitie, 1941, p. 116, 

pi. 18, figs. 2, 3; pi. 19, figs. 1, 2; pi. 22, fig. 2.

Artocarpoides litseafolia (MacGinitie) Wolfe, 1968, 

p. 19.

Dicotylophyllum litseafolia (MacGinitie) MacGinitie, 

1969, p. 130.

Discussion. see p. 23

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Arnold, C. A., 1955, Tertiary conifers from the Princeton 

coal field of British Columbia: University of Michigan 

Museum Paleontology Contributions, v. 12, no. 12, 

p. 245-258.

References Cited 23
Axelrod, D. I., 1966, The Eocene Copper Basin flora of 

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Becker, H. E, 1961, Oligocene plants from the upper Ruby 

River Basin, southwestern Montana: Geological Society of America Memoir 82, 127 p.

Berry, E. W., 1926, Tertiary floras from British Columbia: 

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___1929, A revision of the flora of the Latah Formation: 

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225-265, 16 pis.

Brown, R. W., 1935, Miocene leaves, fruits, and seeds from 

Idaho, Oregon, and Washington: Journal of Paleontology, v. 9, no. 7., p. 572-587, pis. 67-69.

___1937, Additions to some fossil floras of the western 

United States: U.S. Geological Survey Professional Paper 186-J, p. 163-206, pis. 45-63.

___1939, Fossil leaves, fruits, and seeds of Cercidiphyllum: Journal of Paleontology, v. 13, p. 485-499.

___1940, New species and changes of name in some 

American fossil floras: Washington Academy Science 

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___1959, A bat and some plants from the upper Oligocene of Oregon: Journal of Paleontology, v. 33, 

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.1962, Paleocene flora of the Rocky Mountains and

Great Plains: U.S. Geological Survey Professional Paper 375, 119 p., 69 pis.

Dawson, J. W, 1890, On fossil plants from the Similkameen Valley and other places in the southern interior of British Columbia: Royal Society of Canada, 

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Engels, J. C., Tabor, R. W, Miller, F. K., and Obradovich, 

J. D., 1976, Summary of K-Ar, Rb-Sr, U-Pb, Pb, and 

fission-track ages of rocks from Washington State prior 

to 1975 (exclusive of Columbia Plateau basalts): U.S. 

Geological Survey Miscellaneous Field Studies, Map 

MF-710, scale 1:1,000,000.

Engle.r, V., 1909, Monographic der Gattung Tilia: Breslau, 

Wilhelm Gottlieb Korn, 159 p.

Ettingshausen, Constantin von, 1861, Die blattskelete der 

Dikotyledonen mil besondere Rucksicht auf die Untersuchung und Bestimmung der fossilen Plfanzenreste: Kon. Hof. und Staatsdruckerei, Wein, 308 p.

Heer, O., 1876, Beitrage zur Fossilen Flora Spitzbergens: 

Kongliseke Svenska Vetenskaps-Akademie Handlingen Band 14, no. 5, 141 p.

Hickey, L. J., 1973, Classification of the architecture of 

dicotyledonous leaves: American Journal of Botany, 

v. 60, p. 17-33.

___1977, Stratigraphy and paleobotany of the Golden 

Valley Formation (early Tertiary) of western North 

Dakota: Geological Society of America Memoir 150, 

183 p., 55 pis.

Hills, L. V, and Baadsgaard, H., 1967, Potassium-argon 

dating of some lower Tertiary strata in British Columbia: Bulletin of Canadian Petroleum Geology, v. 15, 

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Knowlton, F. H., 1899, Fossil flora of Yellowstone National 

Park: U.S. Geological Survey Monograph 32, pt. 2, 

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Kostermans, A.J.G.H., 1961, The New World species of 

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p. 17-24.

Lesquereux, L., 1872, Tertiary flora of North America in 

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___1874, The Lignitic formation and its fossil flora in 

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24 Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington
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References Cited 25

PLATES 1-16

[Contact photographs of the plates in this report are available, at cost, from U.S. Geological Survey Library, Federal

Center, Denver, Colorado 80225]
PLATE 1

[All natural size]

Figures 1, 2, 7. Sassafras hesperia Berry (p. 12)

Hypotypes UW 31241, 39715, 39717; loc. 8428. 

3-6. Phoebe sp. (p. 11)

Specimens USNM 32676-32679; loc. 8428.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 1

.<K

\

PHOEBE AND SASSAFRAS
PLATE 2

[All natural size unless otherwise indicated]

Figures 1-7. Sassafras hesperia Berry (p. 12)

Hypotypes UW 39709, 39710; USNM 32680; UW 39720; UCMP 9265-9267. Loc. 8428. Figs. 6, 7, 

X 4. Fig. 6 is counterpart of fig. 2; fig. 7 is counterpart of pi. 1, fig. 2.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 2
PLATE 3

[All natural size unless otherwise indicated]

Figures 1-8. Cercidiphyllum obtritum (Dawson) Wolfe et Wehr (p. 12)

Hypotypes UW 31242, 31243; USNM 32681; UW 31244, 31285,39711; USNM 32682. loc. 8428. 

Figs. 4, 7, X 4. Fig. 7 is enlargement of 

fig. 6.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 3

CERCIDIPHYLLUM
PLATE 4

[All natural size unless otherwise indicated]

Figures 1-4. Langeria magnified Wolfe et Wehr (p. 13)

1, 4. Paratypes UW 31246, 31286. Loc. 8428. 2, 3. Holotype UW 39713; loc. 8428. Fig. 2, X 4.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 4

t. % ''v"^3^w -A ; i
PLATES

[All natural size unless otherwise indicated]

Figures 1-4. Langeria magnified Wolfe et Wehr (p. 13)

Paratypes UW 31287-31289. Fig. 3, X 4 (enlargement of fig. 2). Loc. 8428.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 5

\

LANCERIA
PLATE 6

[All natural size unless otherwise indicated]

Figures 1 -4. Macginitiea gracilis (Newberry) Wolfe et Wehr (p. 14)

Hypotypes UW 39714, 31247, 31290; loc. 8428. Fig. 1, X 4 (enlargement of fig. 2).
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 6

MACCINITIEA
PLATE?

[All natural size unless otherwise indicated]

Figures 1-9. Fagopsis undulata (Knowlton) Wolfe et Wehr (p. 15)

Hypotypes UCMP 9280; USNM 32684; UW 39716; USNM 32685-32690. Fig. 1, X4 (enlargement of counterpart of fig. 3), loc. 8428. Figs. 2, 4-7, loc. 11019. Figs. 3, 8, loc. 8428. Fig. 9, X 5, 

loc. 11019.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 7

FACOPSIS
PLATE 8

[All natural size unless otherwise indicated]

Figures 1-8. Alnus parvifolia (Berry) Wolfe et Wehr (p. 15)

Hypotypes USNM 32691, 32692; UW 39721, 31253, 31255, 31254; USNM 32691; UW 31291; loc.

8428. Figs. 7, 8, X 4. Fig. 7 is enlargement of fig. 1.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 8

ALNUS
PLATE 9

[All natural size unless otherwise indicated]

Figures 1-3. Comptonia columbiana Dawson (p. 16)

Hypotypes USNM 32693, 32694; UW 39723. Fig. 1, X 4, loc. 11018. Figs. 2, 3, loc. 8428. 

4-7. Ternstroemites sp. "A" (p. 16)

Specimens UCMP 9290 (counterpart UW 39724); UW 39724, 31259; loc. 8428. Fig. 5, X 4 (enlargement of fig. 4). 

8-11. Betula leopoldae Wolfe et Wehr (p. 15)

8-10. Holotype UW 39722; loc. 8428. Fig. 8, X 4; fig. 10, X 7. 11. Paratype UW 31256, X 4, loc. 

8428.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 9

BETULA, COMPTONIA, AND TERNSTROEMITES
PLATE 10

[All natural size unless otherwise indicated]

Figures 1-4,6. Ternstroemites sp. "B" (p. 16)

Specimens UW 39719,31292, 31293; loc. 8428. Fig. 1, X 4 (enlargement of fig. 3). Fig. 6, X 4

(enlargement of fig. 2). 

5, 7. Tiliajohnsoni Wolfe et Wehr (p. 16)

Holotype UW 39712, UCMP 9291 (counterpart); loc. 8428: Fig. 5, X 4.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 10

TERNSTROEMITES AND TILIA
PLATE 11

[All natural size unless otherwise indicated]

Figures 1-3. Iteasp. (p. 17)

Specimens UW 39725, 31262; loc. 8428. Fig. 1, X 4 (enlargement of fig. 3). 

4-6. Photinia pageae Wolfe et Wehr (p. 17)

Holotype UW 39188; loc. 8428. Fig. 5, X 4; fig. 6, X 7.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 11

t- 5 6

I TEA AND PHOJINIA
PLATE 12

[All natural size unless otherwise indicated]

Figures 1,2,6,7,12. Rhus malloryi Wolfe et Wehr (p. 17)

1,12. Holotype UW 39718; loc. 8428. Fig. 12, X 4. 2, 6, 7. Paratypes UW 31270, 31294, 

31295; loc. 8428. 

3-5. Barghoornia oblongifolia Wolfe et Wehr (p. 18)

Holotype USNM 32695A, B; loc. 8428. Fig. 5, X 4. 

8,10. Koelreuteria arnoldi Becker (p. 21)

HypotypesUW39189, 39190; loc. 8428. Fig. 10, X 5. 

9,13,14. Acersp. (p. 19)

Specimens UW 39728, 31272; USNM 32696. Figs. 9, 13, 15, loc. 8428; Fig. 14, loc. 11018. 

11,15. "Acer" arcticum Heer (p. 18)

Hypotype UW 39726; loc. 8428. Fig. 11, X 4.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 12

RHUS, BARGHOORNIA, KOELREUTERIA AND ACER
PLATE 13

[All natural size unless otherwise indicated]

Figures 1-8. Bohlenia americana (Brown) Wolfe et Wehr (p. 19)

Hypotypes, loc. 8428. 1,4. UCMP 9298; UW 39192 (counterpart). Fig. 1, X 4. 2, 7, 8. UW 31278, 

39736, 31298. 4-6. UCMP 9299; UW 39729 (counterpart). Figs. 5, 6, X 4. Fig. 6 is enlargement of 

fig. 4.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY BULLETIN 1597 

PLATE 13

BOHLENIA
PLATE 14

[All natural size unless otherwise indicated]

Figures 1-4. Cornussp. (p. 21)

Specimens UW 39734, 31276, 39193. Fig. 1, X 4 (enlargement of fig. 2). Loc. 8428. 

5,6. Tsukada davidiifolia Wolfe et Wehr (p. 21)

Paratype UW 39187. Fig. 5, X 4. Loc. 8428.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 14

,- 2

CORN US AND TSUKADA
PLATE 15

[All natural size unless otherwise indicated]

Figures 1 -4. Tsukada davidiifolia Wolfe et Wehr (p. 21).

1, 2, 4. Holotype UW 71095. Figs. 2, 4, X 7.5. 3 Paratype UW 71081. Loc. 8428. 

5. Davidia involucrata S. et Z. (introduced for comparison). Wolfe, s.n., USGS reference coll. 82. X 7.5.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY BULLETIN 1597 

PLATE 15
PLATE 16

[All natural size unless otherwise indicated]

Figures 1-3. Schoepfia republicensis (La Motte) Wolfe et Wehr (p. 22)

Hypotypes USNM 32683, UW 39194. Fig. 2, X 4 (enlargement of fig. 3). Loc. 8428. 

4, 5. Republica hickeyi Wolfe et Wehr (p. 22)

Hypotypes USNM 32697A, B. Fig. 5, X 4. Loc. 8428.
DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

BULLETIN 1597 

PLATE 16

'''''* '''

SCHOEPFIA AND REPUBLICA