Perennials to 2 m or sometimes taller, forming dense clumps from very stout, short woody rhizome 1-1.5 cm diam., with persistent sheath bases. Leaf-sheath stiff, light purplish brown, lowermost often densely villous with long, fine, tubercle-based hairs, others glabrous, keeled above; apex extended upwards at each margin and fused with ligule. Ligule 3.5-9.5 mm, sparsely, shallowly dentate. Collar with some long fine hairs. Leaf-blade 8.5-30-(50) cm × 4-9 mm, flat, stiff, linear-lanceolate, long-tapered, midrib obvious, adaxially with row of long fine hairs near ligule; margins finely scabrid, often crenulate-undulate, tip filiform. Culm 50-175-(250) cm, to 4 mm diam., erect, internodes glabrous. Panicle erect, 15-30 cm, with 10-20-(26) erect to somewhat spreading ± distant racemes; rachis slender, ± angled, glabrous, a few long hairs in raceme axils. Racemes 6-13 cm in lower part of panicle, becoming shorter above; rachis c. 1 mm wide, narrowly winged with scabrid margins, bearing 2 rows of paired, shortly pedicelled spikelets; pedicels sparsely scabrid. Spikelets 2-2.7 mm, closely imbricate, ovate-elliptic, ciliate, somewhat tapered to acute tip, green or purplish. Lower glume 0, upper = lemma of lower floret, 3-(5)-nerved, fringed with long silky hairs, and also bearing sparse appressed silky hairs. Lower floret: lemma 3-(5)-nerved, ± glabrous, fringed by long silky hairs; palea 0. Upper floret: lemma 1.6-1.8 mm, ovate-elliptic, cartilaginous-indurate, creamy, finely punctulate-striolate; palea slightly < and narrower than lemma, margins membranous, widened at base, forming wings enclosing floret; anthers 0.8-1.1 mm, yellow to brownish; stigmas dark purple; caryopsis ≤ 1.5 mm.