Microstegium japonicum (Miq.) Koidz.

This species is very close to Microstegium nudum, but differs mainly in its pedicelled spikelets.

Annual. Culms trailing, rooting at lower nodes, up to 80 cm long, nodes glabrous. Leaf sheaths glabrous, one margin ciliate; leaf blades ovate-lanceolate, 2–5 × 0.6–1.2 cm, glabrous, midvein obscure except near base, base rounded, apex acute; ligule 0.2–0.5 mm. Racemes 3–7, very slender, slightly flexuous, lower becoming divaricate, 4–6 cm; rachis internodes filiform, glabrous, longer than spikelet; spikelets both pedicelled, shorter pedicel ca. 1 mm, longer 2.5–3 mm. Spikelets 3–4 mm; callus very shortly bearded or subglabrous in lower spikelet; lower glume narrowly lanceolate-oblong, back shallowly concave, 2–4-veined, keels scabrid, otherwise smooth, apex attenuate, hyaline, subacute or minutely 2-toothed; upper glume weakly keeled or rounded on back, apex acuminate; lower lemma lanceolate, hyaline, slightly shorter than glumes; upper lemma linear, hyaline, emarginate; awn very fine, flexuous, ca. 1 cm, apex hairlike, tangled; upper palea absent or minute. Anthers 2, 0.5–0.7 mm. Fl. and fr. Jul–Sep.

Mountainsides, forest margins, roadsides. Anhui, Hubei, Hunan, Jiangsu, Jiangxi, Zhejiang [Japan, Korea].

Pollinia japonica Miquel, Ann. Mus. Bot. Lugduno-Batavi 2: 290. 1866; Leptatherum japonicum (Miquel) Franchet & Savatier; Microstegium nudum (Trinius) A. Camus subsp. japonicum (Miquel) Tzvelev.

Microstegium japonicum là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (Miq.) Koidz. mô tả khoa học đầu tiên năm 1929.

日本莠竹（学名：Microstegium japonicum）为禾本科莠竹属下的一个种。