perennial; culms ascending from a creeping, rooting base, 3–5 ft. high, stout, very spongy, internodes mostly exserted; leaves glabrous; sheaths loose, striate, transversely veined, the submerged sometimes spreading, flattened and bladeless; ligules membranous, truncate, up to 1 lin. long; blades linear from a scarcely constricted base, long tapering to an acute point, 4–12 in. by 3–6 lin., flat, flaccid, very closely nerved, scaberulous, margins scabrid; panicle erect, spike-like, cylindric, 6–12 in. by 3 1/2–5 lin.; axis stout, sulcate, smooth; branches spirally arranged, very numerous, adpressed, filiform, smooth, up to 2 lin. long, divided from the base or reduced to fascicles of disc-tipped pedicels; spikelets oblong, acute or subacute, sometimes slightly curved, 1 1/2–2 lin. long, glabrous, olive-green with dark tips; lower glume hyaline, almost orbicular, 1/4– 1/3 the length of the spikelet, finely 5–7-nerved; upper herbaceous-membranous, oblong, prominently 9-nerved; lower floret barren; valve like the upper glume; pale about 3/4 the length of the valve, hyaline; hermaphrodite floret, oblong, obtuse, whitish or yellowish, 1–1 1/3 lin. long; valve chartaceous, obscurely 5-nerved; anthers 1/2 lin. long. null
