Forming large patches with long floating stolons. Leaf-sheath papery, light brown or purplish, minutely scabrid or smooth. Ligule (3)-5-10 mm, membranous. Leaf-blade (9)-17-25 cm × 3-6 mm, folded or flat, minutely scabrid throughout, or only abaxially, or entirely smooth; margins finely scabrid, tip narrowed abruptly to stiff point. Culm (25)-45-75 cm, branched at base, internodes spongy, glabrous, smooth. Panicle (18)-25-45 cm, branches erect, or finally spreading, below in clusters of 2-3 at nodes, borne singly above or sometimes throughout, unequal, longer branches with up to 9 spikelets, shorter branches with 1-2 spikelets; rachis and branches glabrous. Spikelets 20-27 mm, 8-14-flowered, linear-oblong, green, rarely purplish, ± persistent. Glumes unequal, broadly oblong to broadly elliptic, 1-nerved, obtuse, membranous; lower 2-3.5 mm, upper 3-5.3 mm. Lemma (4.5)-5.5-6 mm, 7-nerved, elliptic-oblong, obtuse; nerves finely scabrid, not extending into wide hyaline upper margin. Palea oblong, shortly bidentate with teeth not projecting beyond lemma apex, keels narrowly winged and minutely scabrid. Rachilla c. 1.5 mm, glabrous. Anthers 1.2-2 mm, indehiscent, pollen-sterile. Caryopsis 0.