Description from Flora of China
Panicum simpliciusculum Wight & Arnott ex Steudel, Syn. Pl. Glumac. 1: 96. 1854.
Annual. Culms slender, prostrate and mat-forming, rooting at lower nodes, 10–20 cm tall. Leaf sheaths loose, glabrous or upper margins ciliolate; leaf blades soft, lanceolate, 1–3 × 0.2–0.5 cm, glabrous or hirtellous along veins; ligule hairs 0.1–0.5 mm. Panicle linear, loosely spiciform, 3–8 × 0.5–1 cm, spike-lets borne on short erect branches. Spikelets green or often purplish, 2–3 mm; rachilla internode 0.6–0.8 mm; glumes broadly ovate, herbaceous with membranous margins, lower glume 0.9–1.2 mm, 1–3(–5)-veined, upper glume ca. 1.5 mm, 5–7-veined; lemmas lanceolate, lower lemma 2–2.3 mm, glabrous or puberulous, lower palea equal to lemma; upper lemma 1.6–1.7 mm, pubescent below middle on center back and margins. Anthers 2–3, ca. 0.3 mm. Caryopsis brown at maturity, ca. 1.2 mm. Fl. and fr. Sep–Dec.
Streams, wet valley bottoms. Guangdong, Guizhou, Sichuan, Yunnan [Bhutan, Cambodia, India, Myanmar, Nepal, Sri Lanka, Thailand, Vietnam].