Perennial (?), 8–20 ft. high. Culms much and repeatedly branched upwards, all the ultimate branchlets flowering; internodes terete, smooth, glabrous, more or less (usually shortly) exserted. Leaf-sheaths terete, tight, glabrous, produced into lanceolate erect auricles; ligules membranous, laterally adnate to the auricles of the sheath, truncate, up to over 1 lin. long, ciliolate or eciliolate; blades linear-lanceolate from a much attenuated base or the lower reduced at the base to the stout subterete midrib, long and finely acuminate, up to over 1 1/2 ft. long and over 1 in. wide, thin, green, glabrous or puberulous at the tips, more or less rough all over, scabrid to spinulously ciliate along the margins, midrib quite rounded on the back and stout towards the base, primary lateral nerves up to 12, fine, distant. Inflorescence an often ample decompound spatheate panicle of up to 8 (or more ?) primary mostly mixed 4–13-rayed tiers, the compound rays up to 2 ft. long bearing 2–4 secondary mostly simple few- to many-rayed tiers; spathes except the uppermost usually with well developed blades, glabrous, greenish; rays (simple) very slender, filiform, fastigiate (within the tier), 3/4–1 1/2 in. long. Spatheoles thinly herbaceous, membranous or scarious, pale dull green, sometimes suffused with purple, with short lanceolate to subulate dark green blades or bladeless, 1 1/2–2 1/2 in. long, finally more or less tightly inrolled; peduncles often forming a knee with the rays, ultimately usually exserted and straight. Racemes 2-nate, one sessile, the other with a short bare base, 1–1 1/2 in. long, straight or somewhat flexuous, pale green and silkily-villous on both sides; joints linear, very slightly widened at the tips into a thin obscure cupule, about 1 1/2 lin. long, somewhat transparent, densely ciliate on both sides, hairs upwards to 1 1/2 lin. long, back glabrous; pedicels very similar. Sessile spikelet oblong, subtruncate, including the short obtuse bearded callus 2 1/2 lin. long, glabrous, pale green; callus beard up to 3/4 lin. long. Glumes subequal, membranous, the lower shallowly grooved on the back with 4–5 very fine and close nerves along each keel and 2 more distant and stouter inner nerves bordering the groove, keels very minutely scaberulous; upper glume boat-shaped, obliquely lanceolate-oblong, truncate, sometimes minutely mucronulate, 3-nerved, lateral nerves very faint, villously ciliate on the margins. Lower floret reduced to a hyaline oblong obtuse faintly 2-nerved ciliate valve, 1 1/2 lin. long. Upper floret hermaphrodite; valve very narrow, linear-oblong, minutely 2-lobed, 1 1/2 lin. long, lobes ciliate; awn fine, up to 1 in. long, kneed and twisted about the middle; valvule broad-oblong, truncate, 2-nerved, 1 lin. long. Anthers 1 lin. long; stigmas laterally exserted, orange. Pedicelled spikelets ♂, similar to the sessile; lower glume subherbaceous, flat on the back with minute close and fine nerves, and with a terminal bristle up to over 1/2 lin. long; upper glume oblong, obtuse, hyaline, 3-nerved, ciliate; valve of lower floret as in the sessile spikelet, of upper oblong, emarginate with a minute point in the notch; valvule 0; anthers as in the sessile spikelet.