Habit

Perennials; culms loosely tufted from a hard, knotty base, erect, 6-20 dm tall, scabrous and often branching below the panicles, nodes glabrous. 

Leaves

Sheaths glabrous, or the lower ones sometimes pubescent, margins ciliate; ligule a conspicuous line of hairs ca. 1 mm long, connate at base; blades 6-40 cm long, 3-18 mm wide, flat, pilose on both surfaces or sometimes glabrous, upper surface with a tuft of silky hairs 5-6 mm long at base.

Flowers

Panicles white to yellowish brown, pink or purple, dense, fully exerted from the sheaths, erect to drooping, cylindrical, 10-25 cm long, 1-3 cm in diameter (excluding scabrous portion of the bristles), rachises terete, scabrous; spikelet 1 per involucre, 2-flowered, first floret staminate, outer involucral bristles 13-30, delicate, scabrous, 3-4 mm long, inner involucral bristles 6-14, 15-25 mm long, densely silky plumose; first glume minute or obsolete, second glume thin, papery, slightly longer than lemmas, 5-7-nerved, glabrous, apex acute to slightly aristate; first lemma similar to second glume, ca. 3 mm long, 3-5-nerved, apex acute; first palea hyaline, linear, ca. 2.5 mm long, 2-nerved, apex acute; second lemma indurate, glossy, ovate, ca. 2 mm long, readily separating from the spikelets at maturity, margins enclosing the palea, apex acute, pubescent; second palea similar to second lemma, papery, 1.7-2 mm long, margins inrolled, anthers 1.3-2.1 mm. 

Fruit

Caryopsis pale brown, ellipsoid, ca. 1.5-1.7 mm long, remaining enclosed within the floret.

Seeds

Chromosomes

2n = 18, 34, 36, 45, ca. 48, ca. 52-54, 56, 63, 72, 78