Culms 8–12 m, 4–7 cm in diam., apically pendulous; internodes 40–50 cm, initially gray-white or brown pubescent, with brown tomentose rings below nodes, wall ca. 15 mm thick; nodes flat; branches many, central dominant. Culm sheaths slowly deciduous, leathery, abaxially densely brown strigose; auricles absent; ligule ca. 2 mm, serrulate; blade erect, triangular or long-triangular, base as wide as sheath apex. Leaves 5–9 per ultimate branch; sheaths glabrous; ligule ca. 0.5 mm; auricles absent; blade 12–25 × 1–2.5 cm, base broadly cuneate, lateral veins 5–9-paired. Pseudospikelets 1–3(to many) per node of inflorescence, yellow-green or slightly lilac, ca. 2 × 0.7 cm, somewhat patent when mature; florets 5–8; rachilla disarticulating, joined to florets. Glumes 1 or 2, yellow, leathery; lemmas broadly ovate, ca. 14 × 1.1 mm, 14–16-veined, apex mucronate; palea narrow, keels pilose, 5–7-veined. Lodicules 2 or 3, transparent, ciliate. Filaments 1(–10) mm; anthers yellow, ca. 6 mm. Ovary pyriform, densely pilose; stigmas 2 or 3.
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