Perennial, up to 2 ft. high, forming tufts of flowering and barren culms, with intravaginal innovations. Culms repeatedly geniculate, ascending, terete, slender, smooth and glabrous like the whole plant, 4–5-noded, branched all along, the lower and intermediate branches repeating the features of the main culm, lower internodes wiry, bared by the slipping off of the sheaths, slightly thickened at the nodes. Leaf-sheaths rather firm, tight at first, greenish with purplish bases and dark nodes, finely striate; ligule reduced to a minutely ciliolate rim; blades linear from an equally wide base, tapering to a slender point, 3–6 in. by 2–2 1/2 lin., flat or involute when dry, slightly glaucous, quite smooth, closely and finely nerved, midrib very slender, primary lateral nerves about 3 or 4 on each side, very fine. Panicle oblong to obovoid, up to over 6 in. by 2–5 in., very loose and open, divided to the fourth degree, quite glabrous; common axis slender, finely striate or sulcate or angular upwards, like the primary divisions slightly scaberulous upwards, otherwise smooth; primary branches filiform, at length obliquely or the lowest subhorizontally spreading, approximate in pairs or scanty false whorls or scattered, lower pairs or whorls distant by 1 1/2– 1/2 in., the lowest up to over 3 in. long, undivided for more than 1 in. or only for a few lines, then very loosely divided, the secondary branches very finely filiform, often flexuous, from over 2 to 1/2 in. long, at length divaricate, very loosely divided again, penultimate divisions with 3–2 distant spikelets, like the pedicels subcapillary, very slightly rough; pedicels very obscurely thickened at the tips, the lateral about 1 lin. long, or sometimes much shorter. Spikelets very early gaping, 1 lin. long, variegated with purple. Glumes membranous, finely or obscurely nerved, more or less purple; lower ovate, acute or obscurely mucronulate (acuminate in profile), 5-nerved, appressed except the tips; upper obliquely lanceolate-oblong, acuminate, almost 1 lin. long, 7-nerved. Lower floret ♂: valve similar to the upper glume but broader, acute or subacute, 5-nerved; valvule slightly shorter, oblong, subacute, flaps widened and overlapping at the base; anthers 3/4 lin. long. Upper floret hermaphrodite, oblong, obtuse, 5/8 lin. by 1/4 lin., white, glossy and smooth.
