Plant Species: Iris missouriensis, western iris
Kingdom: Plantae
Phylum: Magnoliophyta -- flowering plants
Class: Liliopsida -- monocotyledons
Order: Liliales
Family: Iridaceae -- iris
Genus: Iris
Species: missouriensis
Common Name: western iris, western flag, western blue flag, Rocky Mountain iris, Rocky Mountain flag, Missouri iris
Species Code: IRMI
Origin: Native to areas that are wet or moist in spring from shrub-steppe to open coniferous forests over much of western North America from southern British Columbia and Alberta south to New Mexico.
Rare: no
Form: forb, up to 35 cm tall, perennial from thick rhizomes (2-3 cm in diameter), forming clumps; roots thick and fleshy.
Mature height: 12-20 inches
Duration: perennial
Longevity: medium lifespan
Habitat Type: wetland, riparian, sometimes in vernally wet sites in uplands
Wetland Indicator Status: FACW+
Leaves: linear, up to 40 cm long, glaucous, tapering to a point.
Flowers: usually 1-2 borne terminally on the stem; perfect; perianth blue to lavender to white with deeper purple veins; sepals oblanceolate to obovate, 5.5-6.5 cm long, recurved; petals oblanceolate, 3.5-6 cm long, erect.
Flower color: blue/purple
Bloom: May, June
Bloom starts on: mid May
Bloom ends on: Mid June
Fruit: capsule, 25-35 mm long; seeds light brown, 4-4.5 mm long, wrinkled, globular to pyriform.
Vegetation type:
Characteristics:
Reproduces both sexually by seed and vegetatively by rhizomes.
23,349 seeds/lb (USDA NRCS Pullman PMC 2005).
19,958 seeds/lb (USDA NRCS PLANTS Database 2009).
Perennating organ is a short, thick rhizome.
Flowers are perfect.
Fruit is a capsule.
2n=38 (Hitchcock et al 1969, Flora of North America Editorial Committee 1993, Baldwin et al 2004).
Pollinated by bees (Cockerell 1902, Lyon 1973). Butterflies and flies rob nectar (Cockerell 1902). Hummingbirds may do some pollination but also rob nectar (Lyon 1973).
A fiber from the leaves was used to make string and rope (USDA NRCS PLANTS Database 2009).
Roots and seeds are poisonous. Roots were used as a arrowhead poison by Native Americans.
Of minor forage value to Rocky Mountain elk in fall (Kufeld 1979).
Comments:
Sun requirement: full sun to partial shade
Soil moisture: moist to wet
Precipitation: 24-35 inches (USDA NRCS PLANTS Database 2009).
Fire:
Hazards: rhizomes are poisonous.
Sowing time: fall
Transplant time: spring
Stratification: cold moist
Seed yield: high
Seed harvest: medium difficulty
Seed first harvest: 3rd season
Seed cleaning: easy
Planting duration: long
Seed insect problem: yes
Seed shatter: low
Seed size: large
Seed harvest date: early to mid August
Seed comments: germination difficult
Key words: native wetland perennial forb
Alternate Genus:
Alternate Species:
Alternate Variety:
Propagation:
2 protocols in the Native Plant Network
Glacier National Park, Montana
Pullman WA Plant Materials Center
Other Propagation Information:
3 weeks cold moist stratification, germinate in light (Chirco & Turner 1986).
Propagate from rhizome cuttings (Kruckeberg 1996).
Sow seeds immediately after collecting. Dried seeds may germinate over 2 years (Phillips 1985).
Seeds need prolonged cold moist stratification (Young & Young 1986).
Reproduces both sexually by seed and vegetatively by rhizomes.
Notes: Iris missouriensis needs a moist site. This native iris puts the cultivated varieties to shame. Fresh seeds germinate well after long stratification, but old seeds are difficult to germinate. Grows from short, thick rhizomes which can be divided to produce new plants. Blooms in mid to late May.
Common names include western iris, western flag, western blue flag, Rocky Mountain iris, Rocky Mountain flag, Missouri iris.
References:
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 10/13/09 online at http://ucjeps.berkeley.edu/interchange.html
Chirco, Ellen, and Terry Turner. 1986. Species Without AOSA Testing Procedures. The Newsletter of the Association of Official Seed Analysts 60(2):2-66.
Cockerell, T.D.A. 1902. Flowers and Insects of New Mexico. American Naturalist 36:809-817.
de Vries, B. 1966. Iris missouriensis Nutt. in Southwestern Alberta and Central and Northern British Columbia. Canadian Field Naturalist 80:158-160.
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 7+ vols. New York and Oxford. Oxford University Press. Online at http://www.fna.org/FNA/
Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.
Kufeld, Roland. 1973. Foods Eaten by the Rocky Mountain Elk. Journal of Range Management 26:106-113.
Kruckeberg, Arthur R. 1996. Gardening with Native Plants of the Pacific Northwest. University of Washington Press. Seattle, WA.
Lyon, David L. 1973. Territorial and Feeding Activity of Broad-tailed Hummingbirds (Selasphorus platycercus) in Iris missouriensis. The Condor 75:346-349.
Phillips, Harry. 1985. Growing and Propagating Wild Flowers. University of North Carolina Press. 341 pp.
Skinner, David M., Paul Warnick, Bill French, and Mary Fauci. 2005.
Characteristics and Uses of Native Palouse Forbs in Landscaping.
USDA NRCS Pullman Plant Materials Center and Palouse Prairie Foundation.
Online at http://www.wsu.edu/pmc_nrcs/Docs/Forbs_for_Landscaping.pdf
USDA NRCS, Pullman Plant Materials Center. 2005. Seed Weights of Some Palouse Native Species. Pullman Plant Materials Center, Pullman, Washington. Online at http://www.wsu.edu/~pmc_nrcs/Docs/Seed_Weights_Palouse_Native_Species.pdf
USDA NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 13 October 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
Young, James A. and Cheryl G. Young. 1986. Collecting, Processing and Germinating Seeds of Wildland Plants. Timber Press, Portland, OR.