Blue Flag Iris

Iris missouriensis Nutt.

This is the only iris native to Wyoming. It is common in moist areas across the state. Its name refers to the Missouri river, not the state; it was first collected by Lewis and Clark on their expedition in 1806. Leaves are silvery-blue, slender, and strap-like. Each flower stalk usually produces several pale blue to purple flowers with yellow highlights on the petals. Though generally considered a wetland plant, it can tolerate very dry conditions and will bloom so long as the soil remains moist in the spring and early summer. They are sometimes considered a weed in hay fields.

Height: 1-2’
Width: expands slowly to form large clumps
Water needs: moderate to high in spring
Exposure: full sun
Availability in nurseries: common
Native range: western North America (WY native)
Plant family: Iridaceae



Photo by Brenna Marsicek