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| ## douglas iris {#douglas-iris .Title-Header}                         |
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| *Iris douglasiana* Herbert                                            |
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| Plant Symbol = IRDO                                                   |
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Contributed by: USDA NRCS National Plant Data Center

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###### Uses

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

*Ethnobotanical*: Iris makes some of the finest cordage; the fibers are
particularly strong and flexible. Only two fibers can be taken from each
iris leaf margin. Huge bunches of leaves were harvested in the fall and
stored until needed. Iris cordage was used for fishing nets, string,
rope, snares, hairnets, and regalia. The fibers are fine like silk, but
surprisingly strong.

Rope was made from fibers, which occur, on the outside of iris leaves.
The iris leaves were gathered in large bundles and a single silky fiber
was taken from each margin of the leaf. None of the other fibers was
used. Using a mussel-shell or abalone \"thumbnail\" the women stripped
the fibers from the leaves. The fibers are detached from the leaves and
scraped clean of all tissues. The men, mostly while sitting around in
their sweathouses twisted the threads on the bare thigh. The men always
knotted the fishing nets. A deer rope is near 20 feet long with 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.\" In spite of the tremendous labor of preparing this
material, the iris fiber was one of the most generally employed in
northwestern California. The threads and cords of this fiber were used
to make fishing nets, camping bags and snares for catching deer, birds,
and other game.![](media/image2.png){width="2.0833333333333335in"
height="2.1458333333333335in"}

Since iris is fine and can be bent at sharp angles, it makes an
excellent starting knot in coiled baskets. It is said that babies were
wrapped in the soft green leaves of *Iris douglasiana* while their
mothers collected manzanita berries, to keep the babies cool and to
prevent dehydration.

The Monache and the Southern Yokuts in California make flour from iris
seed. The Pomo placed acorn meal in a shallow pit and covered the meal
with Iris leaves before pouring water over the meal to leach out tannic
acid.

A poultice of the raw rhizome is especially effective against staph
sores. Externally, iris is successfully used in infected wounds, ulcers,
and fistulas, plus to take away freckles. Only the dry root 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 form the bulk of a medicinal
formula.

Tea from iris roots was used for kidney trouble by several California
Indian peoples (Murphey 1959). The Yana chewed iris roots to cure
coughs. The Modoc used an iris root decoction to soothe sore eyes. A
piece of iris root was inserted in a tooth cavity to kill the nerve, so
the tooth will come out. Tests showed slight bactericidal effects,
slight effects on rabbit pneumonia, and an ascorbic acid content of 4%
(Archer 1957). Roots were burned and the smoke inhaled to alleviate
dizziness. A root decoction was used as a cathartic and emetic, but
large doses could cause severe digestive problems.

*Landscaping & Wildlife*: The beautiful and variable blossoms lend
themselves to landscaping, where they naturalize and require minimal
maintenance. Horticulturally, it is used for rock gardens, ground cover,
borders, wetlands, ponds, and streams. Native irises are free flowering,
most are long lived, require very little attention, and provide an
abundance of seeds. Iris flowers attract insects and birds. Irises
provide nectar to hummingbirds. The mountain beaver (*Aplodontia rufa* )
is also known to feed on the leaves and stems of iris that occur in the
vicinity of its tunnels.

*Invasive Potential*: Irises are sometimes invasive. Irises can become
noxious weeds in pastures, because the 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). The native irises are perennial
herbs, usually evergreen and growing from a creeping, tuberous rhizome.
Irises can be identified by their double row of leaves, which overlap
like praying hands. The leaves are long and linear with parallel
venation. Flower stems are erect and simple. Blossoms vary somewhat in
spacing of the parts, width of sepals, and the inner, erect standards
(petals). *Iris douglasiana* has pale cream to light, dark lavender or
deep reddish purple flowers that bloom from May to June.

###### Distribution

For current distribution, please consult the Plant Profile page for this
species on the PLANTS Web site. *Iris douglasiana* grows abundantly
along the coast from north Santa Barbara County, California, into
Oregon. It is found in shade with moist soils with ample organic matter.
This plant is common in grassy places, especially near the coast, at
elevations generally less than 100 m. It grows naturally in the coastal
prairie and mixed evergreen forest communities.

###### 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. Plants may be watered the year round.
Fertilization increases biomass and seed production. This iris has a
clumping rhizome system, and is readily propagated by plant division in
fall or winter.

When allowed to increase freely, plants will naturalize and eventually
form extensive ground cover. Unless the seed vessels are removed there
will be many volunteer plants, but if inferior flower size or color
appears it should be culled immediately. Irises start growing with the
first cool weather and rains in fall, reaching the height of their
growth in spring and early summer. They go dormant after seed set, in
hot dry summer.

*Propagation by Plant Division*: *Iris douglasiana* is clonal, radiating
outward in growth from the center. The best propagation method for these
is division, in fall or winter after the first new roots are established
but before the flowers form.

Native irises in the wild tend to produce only a small, dry rhizome with
stringy roots, which is difficult to dig. Vigorous garden or greenhouse
plants produce firm, white, growing roots especially in winter and
spring growing seasons, and clumps are easily divided at those time.
Remove a new fan with fleshy roots set in a prepared site, water it, 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 of superior forms.

*Propagation by Seed*: Iris seed is easily collected from the large
capsules. The capsules turn from green to brown and open at the top when
they are ripe. They have to be watched closely, because they disperse
rapidly. Two days after ripening, the seed is gone. 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.

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. Part of the seed waits for
the next year, to increase the probability for good weather conditions
and optimize germination success.

Plant the seedlings in May, when the young plants are usually 3 to 6
inches tall or even taller. Plant from 6 inches to one-foot spacing. If
a natural look is desired, scatter and clump the plantings. Water plants
through the dry season until the roots have established. After the first
year the plants should be self-maintaining without additional watering,
unless there is an unusually hot, dry spell. 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
are serious pests of iris. The Iris Borer stays in the rhizome through
the winter, then metamorphoses, coming out in the spring as a nocturnal
moth. Controlling the moth when its flying, to prevent it from laying
its eggs on the iris, would control the borer. The UC Botanical Garden
used the biological control *Bacillus thuringienis*, but it didn\'t
help. At this time, it is recommended to dig the infected plant out
entirely, put it a plastic bag, and put them 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)

*Cultivars*: Seeds 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*. 4333 Oak Hill Road. Oakland, CA 94605.

Archer, W.A. 1957. *Abstract of pharmacological research*. IN
\"Medicinal Uses of Plants by Indian Tribes of Nevada,\" by Percy Train,
James R. Henrichs and W. Andrew Archer, PP. 108-131. Contributions
Toward a Flora of Nevada, No. 45. Beltsville, Maryland: USDA, Plant
Industry Station. \[Facsimile Reprint: Quarterman Publications,
Lawrence, Massachusetts, 1978.\]

Balls, E.K. 1962. *Early uses of California plants*. University of
California Press. 103 pp.

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 94605.

Cooke, S.S. 1997. *A field guide to the common wetland plants of western
Washington and northwestern Oregon*. Seattle Audubon Society and
Washington Native Plant Society. 414 pp.

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, Fish and Wildlife Service, Region 1,
Stillwater National Wildlife Refuge. 264 pp.

Gunther, E. 1945 rev. 1973. *Ethnobotany of western Washington*.
University of Washington Publications in Anthropology, 10(1). University
of Washington Press, Seattle, Washington.

Hickman, J.C. (ed.) 1993. *The Jepson manual. Higher plants of
California*. University of California Press. 1399 pp.

Hunn, E. & J. Selam and family 1990. *Nch\'i-Wana \"The Big River.\"*
Mid-Columbia Indians and Their Land. University of Washington Press,
Seattle and London. 378 pp.

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

Lawyer, A. et al. January/February 1996. *Growing and hybridizing your
own iris*. Growing Native. The Newsletter of the Growing Native Research
Institute. 15 pp.

Lenz, L. 1958. *Revision of the Pacific Coast irises. A monograph with
drawings and site maps for both species and naturally occurring
hybrids*. Originally published in RSABG\'s publication Aliso in 1958, it
has been reprinted by the Society for Pacific Coast Native Iris (SPCNI).
4333 Oak Hill Road. Oakland CA 94605.

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.

Mason, H.L. 1957. *A flora of the marshes of California*. University of
California. 878 pp.

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

Moser, C.L. 1993. *Native American basketry of southern California*.
Riverside Museum Press. 155 pp.

Murphy, E.V.A. 1959*. Indian uses of native plants*. Mendocino County
Historical Society. 81 pp.

Schmidt, M.G. 1980. *Growing California native plants*. University of
California Press. 366 pp.

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

USDA, NRCS 1999. *The PLANTS database*. National Plant Data Center,
Baton Rouge, Louisiana. \<http://plants.usda.gov\>. Version: 990405.

Warburton, B. date unknown. *The world of irises*. American Iris
Society, 718 West 67th Street, Tulsa, Oklahoma 74132-1808.

###### 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 Sciences Department, University of California, Davis,
California

Revised: 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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