Erect, strongly caespitose perennial with shoots swollen and close-set at base; branching intravaginal. Sheath to 5 cm, striate, densely pubescent at base, long hairs at apex, hairs sometimes forming an abaxial ligule, elsewhere glabrous. Ligule ± 0.5 mm, flat-topped, finely and shortly ciliolate at apex or shallowly crenate. Lamina to 40 cm × 5 mm, flat, abaxially sometimes with scattered long hairs, both surfaces scabrous, margins scabrous. Culms to 2 m, glabrous except for prickle teeth below inflorescence, nodes appressed-pilose. Inflorescence to 30 cm, open; branches drooping, flexuous, rachis smooth to slightly scabrous, branches and pedicels with stiff hairs. Glumes unequal, violet below, hyaline above, 3-nerved, nerves scabrous, produced into awn-like processes to 3 mm, < awn column, lower to 20 mm with long hairs on margins, upper to 15 mm, glabrous. Lemma to 6 mm, tubercular-scabrous, median nerve with long hairs, lobes minute; corona to 1 mm, violet or violet-suffused, glabrous, apex with aconspicuous ring of spines to 1 mm; awn to 70 mm, 1-geniculate; column tightly twisted and long hairy to 25 mm, then shallowly twisted and short stiff hairy to 15 mm above, arista scabrous, to 35 mm, usually intertwined with awns of adjacent florets. Palea 1.5 mm, much < lemma, membranous, nerveless, glabrous. Callus to 4 mm, hairs to 4 mm. Lodicules 2, c. 1 mm, + = palea, nerveless. Anthers penicillate, to 3.2 mm long in chasmogamous flowers, reduced to 1 fertile, 0.5-0.7 mm, and 2 sterile, 0.1-0.2 mm, anthers in cleistogamous flowers.