Herb, perennial, dioecious, caespitose, the base pubescent; cluster and sand-binding roots present. Rhizomes very short, sparsely pilose, mostly covered by glabrous scales. Culms simple or occasionally with 1 or 2 branches, terete, glabrous, striate. Sheaths persistent, appressed, the ligule a short membranous flap formed by the apical margins joining adaxially. Male and female inflorescences similar, of large erect spikelets terminating culms or on slender pedicels at several upper nodes; spikelets with 10–20 flowers and several sterile glumes toward both base and apex; glumes rigid, dark brown or black, obtuse or with a short rigid acute tip. Flowers: tepals 6, 2 outer tepals keeled and with dense red-brown hairs along the keel toward the apex, inner tepals flat. Male flowers with 3 stamens, the anthers exserted. Female flowers with 2 ovary loculi and 2 style branches. Fruit a capsule, compressed, circular in outline. Seeds broad-ellipsoid; surface cells longitudinally elongated and with sinuous walls. Culm anatomy: epidermis with greatly enlarged tanniniferous cells opposite outer vascular bundles; some of these enlarged cells extending partly through the chlorenchyma but others extend to (and interrupt) the parenchyma sheath, the two types of enlarged cells mostly alternating around the culm perimeter in cross-section; chlorenchyma of 1 layer of elongated peg cells; pillar and protective cells absent, central cavity present.
Home