Poa attenuata Trin.

Most botanists recognize Poa attenuata as one of the most complicated and problematic complexes in the flora of C Asia. It has hybridized with P. glauca to form an apomictic complex, which is treated here as P. albertii, while P. attenuata is supposed to be a more or less pure group of xeromorphic alpine populations.

Poa albertii represents an apomictic hybrid complex combining the characters of the parent species P. attenuata s.l. and P. glauca s.l., and perhaps additionally P. versicolor subsp. relaxa.

3300-5500 m.

Tufted perennial without rhizomes; culms (10-) 25-50cm high, erect. Leaf-blades folded or setaceous-involute, 1.5-10cm long, 1-3mm wide, scabrid on the margins; ligule blunt, 1.5-2.5mm long. Panicle oblong, 2.5-9 cm long, contracted; branches solitary or paired, short, ascending, scabrid. Spikelets 2-4-flowered, ovate-elliptic, becoming somewhat wedge-shaped, 4-5.5mm long, often tinged with purple; glumes unequal, 3-nerved, ovate, the lower 2.3-3.3 mm long, the upper broader, (2.5-)3-3.5 mm long; lemmas oblong in side-view, (2-)2.3-3(-3.2)mm long, acute or subacute, ciliate on the keel and marginal nerves, without any wool at the base; palea almost as long as to slightly longer than the lemma, scabrid along the keels; anthers 1-1.8 mm long.

Culms densely tufted, 7–15(–25) cm tall, pale, glabrous or slightly scabrid under the panicle, nodes 2, both near culm base. Shoots usually intravaginal. Leaf sheath usually slightly scabrid, uppermost 1/2 as long as internode; blade folded or inrolled to needle-shape, firm, usually up to 1/2 as long as sheath, 0.3–0.8(–1.5) mm wide, scabrid; ligule 1.5–2.5 mm. Panicle dense, contracted to spiciform, a bit more open at anthesis, 1.5–4 × 0.4–1 cm; branches 2 or 3 per node, 1/5–1/3 as long as panicle. Spikelets lanceolate, (2.5–)3–4.5(–5) mm, florets 2 or 3(–5); rachilla warty; glumes shorter than spikelet, usually equal to first lemma, lemma (2.5–)3–3.5 mm, keel shortly villous for 1/2 of length, marginal veins for 1/3, other parts glabrous; callus webbed or glabrous; palea glabrous between veins. Anthers 1.2–1.5 mm. Fl. Jun–Aug.

Culms dense to loosely tufted, 7–15(–25) cm tall, scabrid (sometimes only slightly), nodes 1 or 2, usually near base. Shoots extravaginal, rarely some intravaginal, sometimes with ascending tillers. Leaf sheath scabrid; blade flat, folded or inrolled, (0.5–)1.5–2(–3) mm wide, scabrid; ligule 1–2.5(–3.5) mm. Panicle oblong, narrow, dense to quite loose, (2–)4–6 × 0.5–1.5 cm; branches 2–5 per node, primary basal branch 2/7–2/3 as long as panicle. Spikelets lanceolate, sometimes tinged with purple or variegated, 3–4(–6) mm, florets 2 or 3; sometimes upper floret viviparous; rachilla smooth, warty or papillose; lower glume 1.5–2 mm, upper glume 2–2.5 mm; lemma narrowly lanceolate, glabrous to uniformly pubescent, apex acuminate; callus webbed or glabrous; palea glabrous or smooth between keels. Anthers 1.2–1.5 mm. Fl. and fr. Jul–Aug. 2n = 28, 42.

Gansu, Nei Mongol, Qinghai, Shaanxi, Sichuan, Xinjiang, Xizang, Yunnan [Afghanistan, Bhutan, India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Tajikistan, Uzbekistan; SW Asia (Iran)].

Gansu, Hebei, Nei Mongol, Qinghai, Shaanxi, Sichuan, Xinjiang, Xizang, Yunnan [Bhutan, India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia (Siberia), Tajikistan, Uzbekistan].

Distribution: Pakistan (N.W.F.P., Gilgit & Kashmir); Siberia, Mongolia and Central Asia.

Himalaya (Nepal, Sikkim), Tibet.

4000-5800 m

Fl. Per.: July

Alpine grasslands; 2000–5600 m.

Dry grasslands, rocky and stepped slopes; 3300–5500 m.

Poa attenuata là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Trin. miêu tả khoa học đầu tiên năm 1835.

渐狭早熟禾（学名：Poa attenuata Trin.）是一种禾本科植物。这种植物分布于中国东北、新疆、内蒙古、河北、山西；俄罗斯、蒙古也有。