74. Poa urssulensis Trinius, Mém. Acad. Imp. Sci. St.-Pétersbourg Divers Savans. 2: 527. 1835.
乌苏里早熟禾 wu su li zao shu he
Culms loosely tufted, 35–60 cm tall, obliquely ascending, nodes 3–5, uppermost 1/3–1/2 way up culm. Shoots extravaginal. Leaf sheaths scabrid, rarely almost glabrous, shorter than internode; blade usually shorter than sheath, flat, or folded, (1–)1.5–2 mm wide, both surfaces scabrid; ligule 0.2–1.5(–2) mm. Panicle effuse, 6–10 × 2.5–5 cm, branches spreading, 2–5 per node, basal primary branch 1/3–1/2 as long as panicle with spikelets in distal 1/2. Spikelets ovate-lanceolate, (3–)3.5–4(–5) mm, florets 2–4; rachilla glabrous or warty, rarely ciliata or pilosa; glumes narrowly lanceolate, lower glume 3–4 mm, upper glume 3.5–4.5 mm; lemma lanceolate, 3–4(–4.5) mm, keel shortly villous for 1/2 of length, marginal veins to 1/3, apex membranous; callus webbed to glabrous; palea smooth and glabrous between keels. Anthers ca. 1.2 mm. Fl. Jun–Aug.
Open grassy and rocky slopes, thickets; (300–)1000–3200(–4200) m. Gansu, Hebei, Heilongjiang, Liaoning, Nei Mongol, Shandong, Xinjiang, Xizang [Kazakhstan, Korea, Mongolia, Russia; Europe].
This is a variable species of hybrid origin, close to Poa lapponica, that might represent a complex of independently arisen populations. The diagnostic characters, such as the pubescence of the lemma and rachilla, and the length of the ligule, vary greatly, both within populations and between populations. Some variants have been recognized as species but are here treated as varieties.