Aristida purpurea, commonly known as purple three-awn, is a perennial bunchgrass native to North America. It has thin stems that grow 10-40 cm tall with branches bearing spikelets with three long, stiff awns at the tip that give the plant its name. Purple three-awn is well adapted to dry, sandy soils and hot climates, making it an important forage grass for grazing animals in the southern Great Plains and southwestern deserts.