Hairy Signalgrass

This is a weedy species recognizable by its short, broad, usually softly hairy leaf blades and secund racemes of rather small spikelets.

Annuals; culm slender, usually decumbent and and branching below, 10-35 cm tall, nodes more or less pubescent. Blades ovate-lanceolate, subcordate, 3-5 cm long, 3-10 mm wide, densely pubescent on both surfaces, one of margins undulate, other side pectinate-scabrous. Inflorescence of racemose racemes, racemes 4-8, 4-6 cm long; rachis more or less villose, scabrous on ridges; pedicels pubescent and bearing stiff hairs as much as 0.5 mm long. Spikelets tomentose, light green but turning light yellow when mature, 2.2-2.5 mm long; lower glume 3-veined, ca. 1/2 as long as spikelet, triangular, acute to obtuse; upper glume and lower lemma equal, acute, 5-7-veined; lower lemma 5-veined, mucronate, enclosing a well developed palea; upper lemma pale, elliptic, mucronate, longitudinally striate and minutely papillose-rugose; anther ca. 1.1 mm long.

Annual. Culms loosely tufted, slender, usually decumbent and branching below, 10–40(–50) cm tall. Leaf sheaths glabrous or pubescent, especially along margins and mouth; leaf blades broadly lanceolate, 1–4 × 0.3–1 cm, both surfaces glabrous to densely pubescent, base rounded or subcordate, margins cartilaginous, scabrous, apex acute; ligule ciliate. Inflorescence axis 3–7 cm; racemes 4–8, (1–)3–6 cm, secund, ascending; rachis triquetrous, ± villous; spikelets mostly single. Spikelets elliptic, 2–2.7 mm, without a stipe, glabrous or pubescent, sometimes transversely bearded below apex, acute or subacute; lower glume 1/3–1/2 spikelet length, clasping, 3-veined, acute; upper glume separated from lower by a slight internode, 5-veined; upper lemma striate and transversely rugulose, apex acute to minutely mucronate. Fl. and fr. Jul–Oct. 2n = 36.

The tropics of southeastern Asia and China. Taiwan, open waste places and on hill.

Mountain or hill slopes, fields, roadsides, other weedy or grassy places. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Taiwan, Yunnan, Zhejiang [Bhutan, India, Indonesia, Japan, Myanmar, Nepal, Philippines, Thailand, Vietnam; Africa].

Panicum villosum Lam., Tabl. Encycl. 1: 173. 1791. Urochloa villosa (Lam.) T.-Q. Nguyen, Novosti Sist. Vyss. Rast. 13: 14. 1966; Veldkamp, Blumea 41: 431. 1996.