5. Microstegium somae (Hayata) Ohwi, Acta Phytotax. Geobot. 11: 155. 1942 [“somai”].
多芒莠竹 duo mang you zhu
Polliniopsis somae Hayata, Icon. Pl. Formosan. 7: 76. 1918 ["somai"]; Microstegium japonicum subsp. somae (Hayata) Koyama.
Annual. Culms slender, trailing, rooting at lower nodes, ascending to 30–40 cm, nodes bearded. Leaf sheaths glabrous, one margin ciliate; leaf blades ovate-lanceolate, 3–4 × 0.3–0.6 cm, glabrous, base rounded, apex acute; ligule 0.2–0.5 mm. Racemes 3–5, very slender, slightly flexuous, 3–8 cm; rachis internodes filiform, glabrous, equaling or longer than spikelets; spikelets both pedicelled, shorter pedicel 1–1.5 mm, longer 2.5–3 mm. Spikelets 4–5 mm; callus hairs 1/4–1/3 spikelet length; lower glume narrowly lanceolate-oblong, back shallowly concave, 4-veined, scabrid, apex 2-cleft, lobes usually mucronate; upper glume weakly keeled, scabrid, apex 2-toothed with 2–10 mm awn; lower lemma linear-lanceolate, hyaline, ca. 2 mm, 2-toothed with up to 1 cm awn; upper lemma similar to lower but slightly shorter; awn ca. 12 mm; upper palea absent. Anthers 2, 0.6–0.8 mm. Fl. and fr. autumn to winter.
Montane forests. Anhui, Fujian, Taiwan [Japan (Ryukyu Islands)].
This species may prove to be a variant of Microstegium japoni-cum with extra awns developed, but it seems sufficiently distinct on the basis of specimens available at present.