Erect, strongly caespitose perennial with shoots swollen and close-set at base; branching intravaginal. Leaf-sheath to 5 cm, striate, densely pubescent at base, long hairs at apex, hairs sometimes forming a contra-ligule, elsewhere glabrous. Ligule ± 0.5 mm, flat-topped, finely and shortly ciliolate at apex or shallowly crenate. Leaf-blade to 40 cm × 5 mm, flat, scabrid, sometimes scattered long hairs abaxially, margins scabrid. Culm to 2 m, internodes smooth except for prickle-teeth below inflorescence, nodes appressed-pilose. Panicle to 30 cm, open; branches drooping, flexuous; rachis smooth to slightly scabrid, branches and pedicels stiff hairy. Glumes unequal, violet below, hyaline above, 3-nerved, nerves scabrid, produced into awn-like processes to 3 mm, < awn column; lower to 20 mm, margins long hairy, upper to 15 mm, glabrous. Lemma to 6 mm, tubercular-scabrid, median nerve long hairy, lobes minute; corona to 1 mm, violet or violet-suffused, glabrous, a conspicuous ring of spines to 1 mm at apex; 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 scabrid, to 35 mm, usually intertwined with awns of adjacent florets. Palea 1.5 mm, membranous, glabrous. Callus to 4 mm, hairs to 4 mm. Lodicules 2, c. 1 mm, ≈ palea. Anthers penicillate, to 3.2 mm in chasmogamous flowers, reduced to 1 fertile, 0.5-0.7 mm, and 2 sterile, 0.1-0.2 mm, anthers in cleistogamous flowers.