2. Hymenachne amplexicaulis (Rudge) Nees, Fl. Bras. Enum. Pl. 2: 276. 1829.
膜稃草 mo fu cao
Panicum amplexicaule Rudge, Pl. Guian. 1: 21. 1805; Hymenachne acutigluma (Steudel) Gilliland; H. pseudointer-rupta C. Mueller; Panicum acutiglumum Steudel.
Culms decumbent, up to 1 m tall, 6–10 mm in diam.; nodes many, brown, glabrous. Leaf blades broadly linear, thick, 30–40 × ca. 2 cm, glabrous or the adaxial surface and margins loosely tuberculate-hairy, base rounded and slightly clasping, apex acuminate. Ligule membranous, 1–2 mm. Panicle 20–40 × 1–2 cm; spikelike, branches 0.5–2 cm, erect, appressed; rachis winged; pedicels scabrous. Spikelets narrowly lanceolate, 4.5–6 × ca. 1 mm, veins smooth at base, otherwise scabrous; both glumes and lower lemma separated by a short stipe; lower glume ovate, ca. 1.2 mm, 1-veined, acuminate; upper glume and lower lemma lanceolate, 3–4 mm, apex with 0.5–2 mm awn; upper lemma ca. 3 mm, margins flat, apex acuminate. Anthers 0.75–1 mm. Caryopsis ca. 1.5 mm, apex rounded. Fl. and fr. summer to autumn.
Streams in shallow water, ricefields; below 1000 m. Hainan, Taiwan, Yunnan [India, Malaysia, Myanmar, Philippines, Thailand, Vietnam].