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| ## western blue flag {#western-blue-flag .Title-Header}               |
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| *Iris missouriensis* Nutt.                                            |
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| Plant Symbol = IRMI                                                   |
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Contributed by: USDA NRCS National Plant Data Center

### 

##### Alternate Names

Blue flag, flag lily, liver lily, water flag, snake lily, wild iris,
lirio, Rocky Mountain iris

##### Uses

*[Warning]{.underline}*: [**Fresh iris roots and rhizomes may be**
**toxic**.]{.underline}

# 

*Ethnobotanic*: Iris makes some of the finest cordage; the fibers are
particularly strong and flexible. Iris cordage was used for fishing
nets, string, rope, snares, hairnets, and regalia. These fibers are very
fine and silky, but surprisingly strong. The threads and cords of this
fiber were used to make fishing nets, camping bags and snares for
catching deer, birds, and other game. In spite of the tremendous labor
of preparing this material, the iris fiber was one of the most generally
employed in northwestern California.

Rope was made from fibers, which occur, on the outer margins of iris
leaves. Huge bunches of leaves were harvested in the fall and stored
until needed. A single silky fiber was taken from each margin of the
leaf. None of the other fibers were used. The men always knotted the
fishing nets. A deer rope is near 20 feet long with a lasso at one end,
and about half an inch in diameter. This loop was set over a deer trail
to catch the head or antlers. Within the set loop over the trail was
spread a delicate network of the same material to draw in the loop. One
Indian stated that \"it takes nearly six weeks to make a rope twelve
feet long.\" ![](media/image2.png){width="1.84375in"
height="3.8847222222222224in"}

A poultice of the raw rhizome is especially effective against staph
sores. Externally iris rhizomes are successfully used on infected
wounds, ulcers, fistulas and to take away freckles. Only the dried iris
root or rhizome should be used internally. Iris is active as a
cathartic, has a stimulating effect on the production of both pancreatic
enzymes and bile, is a strong diuretic, and will stimulate both saliva
and sweat. This is a useful medicinal plant but in general should be
used with care and preferably in combinations where less energetic
plants forming the bulk of a medicinal formula.

*Landscaping & Wildlife*: The beautiful and variable blossoms lend
themselves to landscaping, where they naturalize and require minimal
maintenance. Native irises are free flowering, most are long lived,
require very little attention, and provide an abundance of seeds. Iris
flowers attract both insects and hummingbirds.

### *Invasive Potential*: Western blue flag is considered a noxious weed in pastures, because leaves are unpalatable and bitter. 

##### Status

Please consult the PLANTS Web site and your State Department of Natural
Resources for this plant's current status, such as, state noxious status
and wetland indicator values.

##### Description

*General*: Iris Family (Iridaceae). Western blue flag is a perennial
herb, usually evergreen and growing from a creeping, tuberous rhizome.
Rhizomes on blue flag are between 20-30 mm in diameter, quite large for
a native iris. The leaves are long and linear with parallel venation,
3-9 mm wide, and sometimes purplish. Stems are 2-5 dm and sometimes
branched. Blossoms of *Iris missouriensis* are pale lilac to whitish
with lilac-purple veins.

##### Distribution

For current distribution, please consult the Plant Profile page for this
species on the PLANTS Web site.

##### Establishment

The native irises are excellent in shade situations, even dense shade of
walls and fences (Schmidt 1980). They will tolerate sun for most of the
day in mild areas, and should have afternoon shade and ample water in
the interior regions. These plants are intolerant of frequent summer
water; they should not be planted near lawns or other moisture-loving
plants. However, *Iris missouriensis* does need irrigation to get
established. Fertilization increases biomass and seed production. Irises
start growing with the first cool weather and fall rains, reaching the
height of their growth in spring and early summer. This iris is
rhizomatous, forms clumps, and propagates readily from plant division in
fall or winter.

*Propagation by Plant Division*: In the wild*, Iris missouriensis* tends
to produce only a small, dry rhizome with stringy roots. Vigorous garden
or greenhouse plants produce firm, white, growing roots especially
during the winter and spring growing seasons, allowing easy division of
clumps. Remove a new rhizome fan with fleshy roots and set it in a
prepared site. Keep the newly planted rhizome watered so that it is
moist, and provide shade for a few days if the plant is placed in full
sun. Frequent division appears to keep the plants vigorous, as well as
being the best method of increasing the supply.

# *Propagation by Seed*: Iris seeds are easily collected from the large capsules. These capsules turn from green to brown and open at the top when ripe. Care must be taken when handling seeds because they split very rapidly; two days after ripening the seed has spilled out. Collect capsules carefully to avoid spilling seeds; each capsule has from 20 to 80 seeds. Seeds should be stored in paper envelopes at room temperature until they are planted. The seeds of all species will keep up to 10 years at room temperature.

Plant seeds in 6-inch pots, using a combination of leaf mold and peat
moss. Cover seeds with 1/2 inch of same material. Any good potting soil
that\'s acidic is good for seed germination. Keep soil moist but not
wet. After planting, over-winter the pots outdoors in November or
December. They will come up in 2-3 months, depending on the weather.
Germination increases the second year, because there\'s always a
percentage of hard seeds that won\'t germinate the first year. Delaying
germination until the next year, to increase the probability for good
weather conditions and optimize germination success enhances seedling
survival.

Plant the seedlings outdoors in May, when the young plants are usually 3
to 6 inches tall or even taller. Plants are likely to require watering
the first year during roots establishment. Plant from 6 inches to
one-foot spacing. If a natural look is desired, scatter and clump the
plantings. Plants will begin to bloom by their second year if growth has
been continuous.

Direct seeding is possible in places that can be left undisturbed, as
among shrubs, or among low perennials where the seedlings can be
sheltered. If planting seeds in the ground, autumn is the best time for
seeding; germination begins in two or three months and often continues
beyond that time. A friable seed mixture of sand, loam, and either peat
or screened leaf mold is best, covering the seed with sphagnum moss to
aid in preventing damping-off of seedlings.

##### Management

In autumn, old leaves should be removed from the center of large clumps,
the foliage cut back, and a mulch applied, especially if the irises are
being naturalized in a semi-dry area. Traditional resource management
included harvesting huge bunches of iris leaves in the fall, and storing
these leaves until needed. The fibers are then harvested from the
leaves. This naturally accomplished the pruning and mulching that modern
horticulturists practice to maintain iris beds.

The PCI borer (*Amphipoea americana* var. *pacifica* ) and iris borer
(in the eastern U.S.) are serious pests of iris. The PCI borer stays in
the rhizome through the winter, then metamorphoses, coming out sometime
in the spring as a nocturnal moth. Controlling the moth, to prevent it
from laying its eggs on the iris, will control the borer. However, it is
recommended to dig infested plant out entirely, put it a plastic bag,
and then place it in the garbage can to avoid contamination of other
plants.

Milkweed (*Asclepias* species) and dogbane (*Apocynum cannibinum*) were
traditionally burned by native people in the fall to maintain vigorous
plant production, to stimulate plant growth, to optimize long and
abundant fiber production from leaves and stalks, and to stimulate seed
production. It is probable that iris was burned for the same reasons.

##### Cultivars, Improved and Selected Materials (and area of origin)

IRMI is readily available through native plant nurseries within its
rangeSeeds and plants of selected iris cultivars are available from many
nurseries. It is best to plant species from your local area, adapted to
the specific site conditions where the plants are to be grown. Contact
your local Natural Resources Conservation Service (formerly Soil
Conservation Service) office for more information. Look in the phone
book under "United States Government." The Natural Resources
Conservation Service will be listed under the subheading "Department of
Agriculture."

##### References

American Iris Society. SPCNI, Oakland, California.

Archer, W.A. 1957. *Abstract of pharmacological research.* IN:
*Medicinal uses of plants by Indian tribes of Nevada*, by P. Train, JR.
Henrichs & W.A Archer, Pages 108-131. USDA, Plant Industry Station,
Contributions Toward a Flora of Nevada, No. 45, Beltsville, Maryland
\[Facsimile Reprint: Quarterman Publications, Lawrence, Massachusetts,
1978.\].

Cohen, V.A. 1967. *Guide to the Pacific Coast irises. A monograph with
drawings and photos*. British Iris Society. This monograph has been
reprinted by the Society for Pacific Coast Native Iris (SPCNI), 4333 Oak
Hill Road, Oakland, California.

Fowler, C.S. 1992. *In the shadow of Fox Peak. An ethnography of the
cattail-eater Northern Paiute people of Stillwater Marsh*. Cultural
Resource Series Number 5. USDI, FWS, Region 1, Stillwater National
Wildlife Refuge. 264 pp.

Hutchens, A.R. 1991. *Indian herbalogy of North America*. Shambhala,
Boston & London. 382 pp.

Lawyer, A. & L. (January/February) 1996. *Growing and hybridizing your
own iris. Growing native*. The Newsletter of the Growing Native Research
Institute. 15 pp.

Martin, A.C., H.S. Zim, & A.L. Nelson 1951. *American wildlife and
plants: A guide to wildlife food habits*. Dover Publications, Inc., New
York, New York. 500 pp.

Moore, M. 1979. *Medicinal plants of the mountain west*. Museum of New
Mexico Press. 200 pp.

Strike, S.S. 1994. *Ethnobotany of the California Indians*. Koeltz
Scientific Books, USA\\Germany. 210 pp.

Warburton, B. n.d. *The world of irises*. American Iris Society, Tulsa,
Oklahoma.

##### Prepared By

*Michelle Stevens*

formerly USDA, NRCS, National Plant Data Center

##### Species Coordinator

*M. Kat Anderson*

USDA, NRCS, National Plant Data Center

c/o Plant Science Department, University of California, Davis,
California

Edited: 05dec00 jsp; 20may03 ahv; 060801 jsp

For more information about this and other plants, please contact your
local NRCS field office or Conservation District, and visit the PLANTS
Web site\<[http://plants.usda.gov](http://plants.usda.gov/)\> or the
Plant Materials Program Web site
\<[http://Plant-Materials.nrcs.usda.gov](http://Plant-Materials.nrcs.usda.gov/)\>

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