Purple threeawn

(Aristida purpurea Nutt.)

Purple threeawn is a native perennial bunchgrass found in small dense clumps, 1 to 2 feet tall. It has an open panicle with slender branches that droop from the weight of the seed. The leaves (3-6") are small, firm, and inrolled, dark green turning gr ay or straw colored when cured, while the awns are what give it a purple look. As the name implies, the one-flowered spikelets have three awns, but these are shorter and not as spread out as those of red threeawn. Flowering occurs in spring and again in s ummer.
Distribution and habitat
Purple threeawn grows between 3,300 and 7,000 feet, generally on rocky or sandy plains and slopes. It flowers from May to September.
General information
Purple threeawn is one of the poorest of our common range grasses. It should be grazed in March and April while growing most actively. Palatability is particularly low after the plants mature. The long awns irritate and cause abscesses in the mouths a nd nostrils of grazing animals. Livestock generally avoid purple threeawn for most of the year when other forage is available. Where it is abundant livestock may make moderate use of it in fall and winter after seed shatter.This grass often indicates past range misuse, tending to replace the better grasses under heavy grazing. Light use, winter gazing or complete rest for these areas will give other grasses a chance to increase.