Annual, slender, rather stiff tufts or solitary shoots, 3-60-(80) cm, with panicles usually conspicuously exserted above uppermost leaf-sheath. Leaf-sheath hyaline, glabrous, green to purplish, lower sheaths darker brown with paler ribs. Ligule 0.2-0.5 mm, a membranous, truncate rim. Leaf-blade (1.5)-3-10 cm × 0.8-1.5 mm, flat or involute, abaxially glabrous, adaxially short-ciliate on ribs; margins and acute tip scabrid. Culm 3-40 cm, erect or decumbent at base, internodes glabrous, or sparsely to more densely hairy. Panicle 1.5-12-(17) cm, secund, erect or slightly nodding, lanceolate to narrow-oblong, often rather lax below and with upper branches erect-appressed, sometimes reduced to a single spikelet; rachis, branches and stiff pedicels scabrid on angles. Spikelets (8)-10-20-(25) mm, 5-7-flowered, uppermost 1-2-(3) florets Ø, cuneate or oblong; flowering usually cleistogamous. Glumes very unequal with broad green nerves and hyaline margin, acute to apiculate; lower 2.5-4.2 mm, ½-¾ length of upper, 1-nerved, subulate, smooth, upper 4.7-7.8 mm, 3-nerved, oblong-lanceolate, midnerve scabrid near tip. Lemma 5.5-7.5-(10.5) mm, 5-nerved, firmly membranous, rounded, elliptic-lanceolate, scabrid; awn 4.5-11 mm, fine, minutely scabrid. Palea keels scabrid, interkeel scabrid near apex. Callus glabrous. Rachilla glabrous. Anthers usually 1, rarely 2, (0.2)-0.4-0.6 mm, or 0.8-1.5 mm. Caryopsis (2)-3-4.2 × 0.5 mm.