67. Poa nemoralis Linnaeus, Sp. Pl. 1: 69. 1753.
林地早熟禾 lin di zao shu he
Culms loosely tufted, 30–80(–100) cm tall, erect or lightly geniculate, nodes 3–5(–6), uppermost at or above 1/2 way up. Leaf sheaths smooth or scabrid, shorter than blade; blade flat, soft, 5–12 cm × 1–3 mm, margins and both surfaces scabrid; ligule 0.2–1(–1.5) mm, truncate to obtuse. Panicle slender, 5–15(–22) cm, branches spreading, 2–5 per node, basal primary branch 1/2–2/3 as long as panicle with spikelets in distal 1/2. Spikelets lanceolate, 3.5–5(–6) mm, florets mostly 3; rachilla pilose; glumes narrowly lanceolate, 2.5–3.7 mm; lemma oblong-lanceolate, 2.5–3.7(–4.2) mm, keel shortly villous for 1/2 of length, marginal veins to 1/3, apex membranous; callus sparsely webbed, rarely glabrous; palea smooth and glabrous between keels. Anthers 1.3–1.5 mm. Fl. May–Jun. 2n = 14, 35, 70.
Forested slopes, shady and moist places, forest margins, grassy places among thickets; 1000–4200 m. Gansu, Guizhou, Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan [Bhutan, India, Japan, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Tajikistan, Uzbekistan; SW Asia, Europe, naturalized in North America].
Poa nemoralis is represented by many cytological races, which form a huge series of agamic complexes of very variable hybrid populations. Such a complex, arising from hybridization with P. palustris, is treated here as P. lapponica and is common in NE Europe, Siberia, and Mongolia. The many hybrids with P. versicolor subsp. relaxa and P. nemoraliformis, reported by Ovczinnikov (in Ovczinnikov & Chukavina, Fl. Tadzhiksk. SSR 1: 144. 1957), also seem to form agamic complexes. Poa nemoralis commonly hybridizes with P. glauca in Scandinavia, but obvious hybrids between these species have not yet been found in China. Pure populations of P. nemoralis usually occur in broad-leaved forests, quite far from P. nemoraliformis, P. palustris, and P. versicolor subsp. relaxa.