16. Poa sibirica Roshevitz, Izv. Imp. S.-Peterburgsk. Bot. Sada. 12: 121. 1912.
西伯利亚早熟禾 xi bo li ya zao shu he
Perennials, rhizomatous; shoots extravaginal and a few intravaginal. Culms erect, decumbent at base, (20–)40–120 cm tall, 1–4 mm in diam., loosely tufted, shiny, smooth or sparsely short scabrid below panicle, nodes 3 or 4, 1 or 2 exserted, with a few persistent whitish sheaths. Leaf sheaths green, compressed, with keel up to 0.4 mm deep, smooth or finely scabrid, glabrous, 8–20 cm, 1–2 or more × as long as blade, uppermost closed for 1/2–2/3 of length; blade flat or folded, thin, 4–25 cm × (1.5–)2–6(–8) mm, abaxially smooth, adaxially smooth to scabrid, margins scabrid, apex prow-tipped, of tillers often folded, abaxially smooth; ligule (0.5–)1–2.7 mm, abaxially smooth or scabrid, glabrous or puberulent, apex truncate to obtuse, irregularly dentate, collar margins smooth or coarsely scabrid, glabrous. Panicle loosely contracted to wide open, exserted, (4–)6–15(–18) cm, longest internodes 1–4 cm; branches ascending to spreading, 2–5 per node, slender, round to weakly angled, proximally smooth or scabrid along angles throughout, longest 3–9 cm with 3–17 moderately crowded spikelets in distal 1/2. Spikelets pale green to dark purple, (3.5–)4–5.5(–6.5) mm, florets 2–5; vivipary absent; rachilla internodes 0.5–1 mm, smooth or scabrid; glumes lanceolate, acute, upper keel and veins scabrid, lower glume (1.2–)2–2.5(–3.5) mm, 1(or 3)-veined, upper glume 2.5–3(–4.5) mm, 3-veined; lemmas pale green or sometimes violet to dark purple above, 2.5–4(–5.5) mm, proximally minutely bumpy to scabrid, distally scabrid, glabrous throughout (sometimes obscurely strigulose on keel base), keel scabrid, intermediate veins prominent, apex and margins narrowly membranous, apex acute; callus glabrous; palea minutely bumpy and with slender hooks between keels, keels finely and densely scabrid to subciliate for (1/2–)2/3–3/4 of length, 40–60 hooks per keel. Anthers 1.5–2.5 mm. Fl. and fr. Jun–Jul.
Forest margins, meadows among thickets, grassy places on slopes in river valleys, subalpine meadows; 1700–2800 m. Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Shanxi, Sichuan, NW Xinjiang, Yunnan [Kazakhstan, Korea, Kyrgyzstan, Mongolia, Russia (Far East, Siberia); Europe (Russia to W of Ural Mountains)].