蔓生莠竹 man sheng you zhu

Andropogon fasciculatus Linnaeus, Sp. Pl. 2: 1047. 1753; A. formosanus var. minor Rendle; Microstegium gratum (Hackel) A. Camus; M. monanthum (Nees ex Steudel) A. Camus; M. vagans (Nees ex Steudel) A. Camus; Pollinia ciliata var. breviaristata Rendle; P. grata Hackel; P. monantha Nees ex Steudel; P. vagans Nees ex Steudel.

Perennial. Culms rambling, rooting at base, branching, up to 4 m long, internodes sometimes pubescent, nodes pilose. Leaf sheaths pubescent to tuberculate-hispid, at least below blade, one margin ciliate; leaf blades narrowly elliptic, 10–18 × (0.5–)0.8–2 cm, pilose, more densely on abaxial surface, base sometimes setose, apex acuminate into a setaceous point; ligule 1–2 mm. Racemes 3–12, purplish, flexuous, fastigiate, 7–12 cm; rachis internodes linear, slightly inflated upward, shorter than spikelet, margins ciliate. Sessile spikelet 2.8–4 mm; callus hairs 1–1.5 mm; lower glume elliptic-oblong, back shallowly grooved or almost flat, scabrid-hispidulous, 2-veined between keels, upper keels stiffly pectinate-ciliate, apex subentire; upper glume sharply keeled, apex acuminate or with a brief mucro; lower floret usually absent; upper lemma ovate, ca. 0.5 mm, rounded to emarginate; awn geniculate with distinct column, 5–8 mm; upper palea lanceolate, 0.7–1.2 mm, obtuse or 3-dentate. Anthers 3, 1.5–2.5 mm. Fl. and fr. Aug–Jan. 2n = 80.

Forming extensive colonies, moist banks, slopes, usually in shade. Guangdong, Guizhou, Hainan, Hubei, Sichuan, Yunnan [Bhutan, India, Indonesia, Malaysia, Myanmar, Nepal, Thailand, Vietnam; Africa].

Normally the lower floret is completely absent in this species. In a few gatherings (including the type of Pollinia vagans) the lower floret is represented by a well-developed palea supporting stamens. A specimen from Hong Kong has a rudimentary lower lemma, but no lower palea. The presence or absence of parts of the lower floret appears to be of no taxonomic significance.