Paspalum virgatum L.

Perennials; rhizome short, culm tufted, erect, 1-2 m high. Blade stiff, margins sharp with siliceous bodies; sheath keeled, compressed, lower ones softer, papery. Inflorescence of racemose racemes, numerous; rachis prominently covered with papillate bristles. Spikelets obovate, 2.2-2.5 mm long, densely 4-rowed, brownish, margins hairy, prominent at summit; lower glume reduced; upper glume 3- veined, convexed on dorsal part, subequal to spikelet, margins and summit soft hairy; lower lemma and upper glume subequal, with marginal hairs, flat on dorsal part, upper floret brownish, coriaceous, slightly shorter than spikelet.

Perennial from short rootstock. Culms robust, forming a dense tussock, erect, 1–2 m tall. Leaf sheaths compressed, usually papillose-hirsute at margins and summit; leaf blades linear, flat, stiff, 30–75 × 1–2.5 cm, margins serrate, apex acuminate; ligule 2–3 mm. Inflorescence axis 10–30 cm; racemes up to 20, 5–15 cm, ascending or drooping; spikelets paired, in 4 dense rows; rachis 0.5–1.5 mm wide, scabrous, glabrous or with a few setae. Spikelet brownish, obovate, 2.2–3 mm, acute; upper glume membranous, 3–5-veined, dorsally puberulous, margins fringed with short silky hairs above middle; lowerlemma resembling upper glume but glabrous; upper lemma brownish, as long as spikelet, coriaceous, finely punctulate-striate, subacute. Fl. and fr. summer–autumn. 2n = 40, 80.

Originally from Jamaica, now naturalized elsewhere. Taiwan, naturalized in the northern part.

Moist or swampy ground, naturalized. N Taiwan [native to America from the United States to Brazil].