Herb, perennial, dioecious, rhizomatous, forming dense clumps or large diffuse patches; cluster roots present. Rhizome stout, 0.5–1 m long, 4–7 mm diam. Culms often dimorphic with vegetative culms much-branched; spaced up to c. 3 cm apart on the rhizome, 0.1–1 m long, mostly terete but compressed above branching nodes, glabrous to densely pubescent, 1–2 mm diam. toward the base; initially straight and erect, with branches straight to flexuose; internodes 3–7 cm long. Sheaths 3–20 mm long, striate, green to brown, glabrous to pubescent, acute to obtuse; lamina erect, terete or compressed, 1.0–2.5 (–5.0) mm long. Male spikelets sessile, terminal and axillary on secondary branches, narrow-ovoid, 3.0–6.5 mm long; glumes 4–11, all fertile or rarely the lowest glume sterile, obovate, obtuse, 2.2–2.8 mm long, brown, glabrous or apically pubescent; mucro 0.7–1.0 mm long. Female spikelets terminal on culm and branches, ± obovoid, 7–11 mm long; glumes 1–4, uppermost glume fertile, ovate to elliptic, glabrous or pubescent, obtuse, 3–6 mm long; mucro 1–2 mm long. Male flowers: tepals 6, lanceolate, acute to obtuse, red-brown-hyaline; outer tepals 2.2–3.0 mm long; filaments 2.1–3.0 mm long; anthers 1.1–1.4 mm long, exserted. Female flowers: outer tepals rigid, ovate, 4.5–7 mm long; inner tepals 3–5 mm long, membranous, flat or the margin incurved; ovary 1-locular; style unbranched (rarely 2-branched), stout, recurved or recoiled. Capsule c. 4 mm long; capsules infrequently developing. Seed: surface cells slightly convex, lobed, separated from adjoining cells by deep narrow crypts. Culm anatomy: chlorenchyma of 2 or 3 layers of short peg cells, interrupted by pillar cells and partial sclerenchyma ridges opposite the outer vascular bundles, central cavity mostly present.
Home