2. Acroceras tonkinense (Balansa) C. E. Hubbard ex Bor, Indian Forest Rec., Bot. 1(3): 78. 1938.
山鸡谷草 shan ji gu cao
Panicum tonkinense Balansa, J. Bot. (Morot) 4: 140. 1890; Neohusnotia tonkinensis (Balansa) A. Camus.
Perennial. Culms up to 100 cm tall, nodes densely pubescent with soft white hairs. Leaf sheaths glabrous or with tubercle-based hairs, one margin tuberculate-ciliate; leaf blades lanceolate, 10–20 × 1–3 cm, glabrous or abaxial surface pilose, margins thickened, pectinate-ciliate at base, scabrous, midvein prominent abaxially, apex narrowly acuminate; ligule ca. 1 mm, obtuse. Panicle open, 15–25 × 5–10 cm, axis and branches stiff, scabrous; racemes ascending, with secondary branching; spikelets widely spaced, paired or single in upper part. Spikelets 5–5.5 mm; lower glume broadly elliptic, 3/4 spikelet length, 5-veined; upper glume and lower lemma as long as spikelet, 5-veined, apex slightly thickened; lower palea hyaline, narrow; upper lemma smooth, shining, slightly shorter than spikelet, apex thickened and protruding. Fl. and fr. Aug–Oct.
Moist places in forest shade. Hainan, Yunnan [India, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam].
This is a more robust species than Acroceras munroanum, with larger leaves and harshly scabrous leaf margins and inflorescence.