Microstegium somae (Hayata) Ohwi

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.

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)].

Polliniopsis somae Hayata, Icon. Pl. Formosan. 7: 76. 1918 ["somai"]; Microstegium japonicum subsp. somae (Hayata) Koyama.