Gregarious shrub with annual culms from a central rootstock; culms 2-3.5 m high, 7-15 mm in diameter; nodes swollen, glabrous or hirsute, bearing numerous fasiculate branches geniculate at the joints, the flowering and leaf-bearing branches on different culms; internodes 15-30 cm long. Culm-sheaths straw-coloured, striate, as long as or longer than the internodes, up to 30 cm long and 7.5 cm wide at the base, glabrous and minutely scabrid on the outside, hairy in the upper half on the inside, ciliate on the margins, attenuate in the upper two-thirds to a narrow truncate ciliate, 25-5 mm wide tip; imperfect blade 1.2-5 cm long, 23 mm wide, subulate, recurved; ligule up to 12 mm long, dentate. Leaf-blades 7.5-10 cm long, 5-8 mm wide, on young shoots exceptionally up to 30 cm long and 2.5 cm wide, linear, attenuate at the base into a petiole up to 25 mm long, setaceous at the tip, scabrid above, minutely pubescent and eventually glabrous beneath, scabrid on the margins, transverse veinlets absent but with many pellucid glands having the appearance of transverse veinlets when dry. Inflorescence on leafless culms, consisting of paniculate falcate racemes fascicled at the nodes and subtended by short linear or lanceolate membranous bracts. Spikelets 1.2-1.8 cm long, without bracts below the glumes, fertile florets 1-2 with a sterile floret or free rhacilla above; glumes unequal, the lower about 8 mm long, 3-5-nerved, the upper about 10 mm long, 7-9-nerved; lemma about 12 mm long, subacute, mucronate, scabrid, 7-9-nerved, ciliate at the tip; palea equalling or exceeding the lemma, bifid at the apex, 2-keeled, lodicules ovate or obovate, one a little narrower, hyaline, somewhat swollen at the base, 3-nerved, fimbriate on the margins. Caryopsis linear, about 12 mm long, furrowed on the back, surmounted by the base of the bifid style.