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Taxon  Report  
Iris missouriensis  Nutt.
Rocky mountain iris,   Western blue flag
Iris missouriensis is a perennial herb that is native to California, and also found elsewhere in western North America.
Siskiyou Del Norte Modoc Humboldt Shasta Lassen Trinity Plumas Tehama Butte Mendocino Glenn Sierra Yuba Lake Nevada Colusa Placer Sutter El Dorado Yolo Alpine Napa Sonoma Sacramento Mono Amador Solano Calaveras Tuolumne San Joaquin Marin Contra Costa Alameda Santa Cruz Mariposa Madera San Francisco San Mateo Merced Fresno Stanislaus Santa Clara Inyo San Benito Tulare Kings Monterey San Bernardino San Luis Obispo Kern Santa Barbara Ventura Los Angeles Riverside Orange San Diego Imperial

Bloom Period
Genus: Iris
Family: Iridaceae  
Category: angiosperm  
PLANTS group:Monocot
Jepson eFlora section: monocot

Toxicity: Do not eat the leaf or underground parts of this plant.

Wetlands: Occurs usually in wetlands, occasionally in non wetlands

Communities: Yellow Pine Forest, Red Fir Forest, wetland-riparian

Name Status:
Accepted by JEF + PLANTS

Alternate Names:
PLANTSIris missouriensis var. arizonica
PLANTSIris missouriensis var. pelogonus
JEFIris montana
PLANTSIris pariensis
PLANTSIris tolmieana
Information about  Iris missouriensis from other sources
Nursery availability from CNPLX
This plant is available commercially.
Jepson eFlora


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[Wikipedia] Range, Description, Uses, Toxicity: Iris missouriensis (syn. I. montana) is a hardy flowering rhizomatous species of the genus Iris, in the family Iridaceae. Its common names include western blue flag, Rocky Mountain iris,[2] and Missouri flag. It is native to western North America. Its distribution is varied; it grows at high elevations in mountains and alpine meadows and all the way down to sea level in coastal hills.[3][4] Description The three, usually light blue, sepals have purple lines and surround the three smaller darker-blue petals. The inflorescence usually consists of one or two flowers, exceptionally three or four. Each flower has three light to dark blue, spreading or reflexed sepals lined with purple and three smaller upright blue petals.[5][6][7][8] They produce a large fruit capsule.[9] The plant populations often spread outwards from the older plants, leaving a dead opening in the center of a growing ring.[9] Uses Some Native American tribes made cordage from the plant's stems and leaves.[10] Some Plateau Indian tribes used the roots to treat toothache.[11] The Navajo used a decoction of the plant as an emetic.[12] Plains Indians are said to have extracted the toxin irisin from the plant to use as arrow poison.[9] The Zuni apply a poultice of chewed root to increase the strength of newborns and infants.[13] This iris is listed as a weed in some areas, particularly in agricultural California. It is bitter and distasteful to livestock and heavy growths of the plant are a nuisance in pasture land. Heavy grazing in an area promotes the growth of this hardy iris.[7] Toxicity The plant is toxic, particularly the rootstalks, which contain the potentially lethal irisin.[9] (contributed by Mary Ann Machi)

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2024. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 05/19/2024).