Scarlet Locoweed (Astragalus coccineus)
Pea Family

Found: Canyons and gravelly slopes, 2,000'–7,000', in Mojave and Colorado deserts.

About: Members of this genus create “locoism” in grazing animals. Locoweed is generally ignored by animals, but when graze is scarce they may resort to it. The weed is apparently habit forming and causes a gradual wasting effect on animals.

The “loco” characteristic comes from the behavioral changes in animals. Horses may jump over pebbles in a trail and will not take a lead. Animals startle when raised from the stupor created by the plant.