Rhizomatous perennial with extravaginal branching, and much branched, multinoded stems of many cauline, often stiff hairy leaves, and often purpled spikelets on erectly branched narrow panicles. Branching extravaginal; rhizomes sometimes short; cataphylls chaffy. Leaf-sheath tight, short hairy or glabrous, overlapping node above, keel obscure. Ligule to 0.5 mm, finely erose, ciliate. Auricles 2, small, margin hairs (c. 3 mm) few. Collar short stiff hairy. Leaf-blade 5-25 cm × 2-5 mm wide, abaxially and adaxially abundantly stiff hairy sometimes more so abaxially, midrib prominent; margins with close-set, sharp teeth, retrorse below antrorse above, sometimes thickened, white, undulating. Culm to 85 cm, internodes many, glabrous, sometimes longitudinally grooved. Panicle 10-25 cm, narrow, slender, internodes short, branches erect to 5 cm, > internodes, rachis longitudinally grooved; branches and pedicels finely scabrid. Spikelets 25-35 mm, on slender finely scabrid pedicels; Ø lemmas often purple or purple-suffused. Glumes ± equal, 1-nerved, entire, often purple, margins ciliate, distant from Ø lemmas, < callus hairs; lower to 0.8 mm, upper to 1.5 mm. Callus 1-1.5-2 mm, clothed in hairs to 2 mm. Lower Ø lemma 12-20-30 mm, 5-7-nerved, scabrid, margin short (0.25 mm) hairy, awn > ½ lemma length; upper Ø lemma 17-26-35 mm, prickle-toothed throughout or glabrous below and prickled above, 5-7-nerved, awn > ½ lemma length; callus hairs 0. ☿ lemma 5-7-9 mm, 5-7-nerved, shining, smooth except for teeth on upper ½ of keel, shortly awned (0.1-1.0 mm) from shortly lobed ciliate apex, margins hyaline; when cleistogamous often included by upper Ø lemma. Palea membranous, hyaline, produced into a mucro or becoming acute, apex ciliate; dimorphic, 4-6-8 mm in chasmogamous flowers, 2-3-4 mm in cleistogamous flowers. Lodicules 2, 1-2-2.7 mm in chasmogamous flowers occasionally hair-tipped, falling with caryopsis; 0 in cleistogamous flowers. Stamens 2-3-4; anthers 1.5-2.5-4.2 mm in chasmogamous flowers, (1)-2-3-4, 0.2-0.4-1.0 mm in cleistogamous flowers. Gynoecium: ovary 0.8-1.2 mm; stigma-styles 1.2-2.5-4.0 mm in chasmogamous flowers, 0.8-1.4-2.0 mm in cleistogamous flowers, stigma branches reaching ovary. Caryopsis laterally compressed, finely wrinkled, often falling free, 3.5-4.5-5.5 mm in chasmogamous flowers, 2-3.8-5.8 in cleistogamous flowers; embryo 0.6-1.0 mm. 2n= 48.