Red threeawn

(Aristida purpurea var. longiseta)




Synonyms
Aristida longiseta Steud.
Description
Red threeawn is a native, perennial, 6 to 15 inches tall, growing in thick bunches. Its culms are usually short and branched. Old leaves from the year before give red threeawn clumps a grayish green color. Its new leaves, short, rather stiff, and inro lled, green up in late spring and cure to tan. The 'red' of red threeawn comes from the immature awns. Both the whole inflorescence and the spikelets themselves vary a lot, from flexuous to stiffly erect, contracted to open, drooping to spreading. Red thr eeawn has three relatively stout awns, 2 to 3 inches long, spreading out at right angles (compare Purple threeawn).
Distribution and habitat
Red threeawn is found between 3,000 and 6,000 feet, most commonly on dry, sandy or gravelly plateaus and hills. It is fairly widespread and in some places abundant. Although often an indicator of range deterioration, red threeawn may indicate only tha t the site is arid and has a well-drained soil. Flowering occurs in spring and again in summer.
General information
Red three-awn has a low palatability rating, much less than blue grama or the other grasses with which it is usually found. Because of its abundance in some areas, however, it furnishes rather large amounts of forage, particularly from late July to ea rly September. During the fall and winter when the plants are dry it has little value. Red threeawn readily increases on heavily grazed ranges at the expense of the better forage plants. Proper grazing regimes, temporary exclusion, or winter-only grazing can improve these areas.