Western Blue Flag
Iris missouriensis
Family: Iridaceae
A perennial forming large colonies from rhizomes that can spread almost indefinitely under the right conditions. Plants grow to almost 2’ tall. Rocky Mountain iris makes a showy ornamental. Light blue to purple flowers appear spring through fall.
It prefers part sun in the low desert and high moisture levels. It can be propagated from both seed and rhizomes. It is native to mountainous areas as high as 9000’ in elevation and can take whatever cold we throw at it in our region.
The flowers attract hummingbirds. Larval host for many moth species.
Photo by Liz Makings, SEINET
Iris missouriensis on iNaturalist
Some Native American tribes made cordage from the plant's stems and leaves. Some Plateau Indian tribes used the roots to treat toothache. The Navajo used a decoction of the plant as an emetic. Plains Indians are said to have extracted the toxin irisin from the plant to use as arrow poison. The Zuni apply a poultice of chewed root to increase the strength of newborns and infants. The plant is widely cultivated in temperate regions.
Wet meadows, stream banks, seeps, aspen woods, montane habitats, 6000-9500 ft. in western and southwestern U.S., northern Mexico.