日本早熟禾 ri ben zao shu he

Basionym: Poa nipponica Koidzumi, Bot. Mag. (Tokyo) 31: 256. 1917.

Culms 20–40 cm tall, 1–2 mm in diam. Uppermost leaf sheaths slightly longer than blade, closed for ca. 1/2 of length; ligule 1–1.6(–2) mm. Panicle branches proximally sparsely to moderately scabrid angled from base, distally sparsely to moderately densely long scabrid angled; lower glume 2.5–3.3 mm, upper glume 2.5–3.4 mm; lemmas with intermediate veins glabrous or proximally pilulose to short villous, smooth between veins; palea keels pilulose only. Fl. and fr. May–Jul. 2n = 42, 56.

Thickets, moist meadows on sunny slopes. Liaoning [Korea, Japan].

Poa nepalensis var. nipponica is generally more robust than var. nepalensis, and the lower glume to lower lemma length ratio is slightly greater. It is common in Japan, but seems to be absent from most of China.