Poa versicolor in Flora of China @ efloras.org

77. Poa versicolor Besser, Enum. Pl. 41. 1821.

变色早熟禾 bian se zao shu he

Poa attenuata Trinius var. versicolor (Besser) Regel.

Culms erect, densely tufted, (25–)30–60(–75) cm tall, nodes 2–3(–5), uppermost to 1/3 way up culm. Shoots extravaginal. Leaf sheath scabrid, usually longer than blade; blade narrowly linear, flat or inrolled, 0.5–2.5(–3) mm wide, scabrid; ligules 1–3(–7) mm. Panicle contracted, narrow to spiciform, (4.5–)6–15(–17) × 1–3(–5) cm; branches erect, 1 or 2 per node, (1/5–)1/4–1/3(–1/2) × as long as panicle. Spikelets lanceolate, (3–)3.5–6(–7) mm, green or tinged with purple, apex yellow, ± violet; florets (2–)3–5(–7); rachilla warty, rarely pilose; glumes subequal, lanceolate to oblong-lanceolate, 3–4.2 mm; lemma oblong-lanceolate, 3.2–4 mm, keel usually shortly villous for 1/2 of length, marginal veins for 1/3, area between veins glabrous or pubescent; callus webbed to glabrous; palea glabrous or pubescent between keels. Anthers 1.3–2 mm. Fl. Jun–Aug.

Meadows along forest and thicket margins, grasslands on slopes, steppes; 200–4300 m. Anhui, Gansu, Hebei, Heilongjiang, Henan, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan [Japan, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Nepal, Russia, Tajikistan, Turkmenistan, Uzbekistan; SW Asia, Europe].

Poa versicolor is supposed to be a xeromorphic derivate of P. palustris. It is interpreted here as a widespread complex of feebly differentiated geographic races, and it is perplexingly polymorphic. Poa versicolor s.s. is distributed in S Europe and is absent from China. All subspecies in this complicated species seem to be close allies, differing from one another by complexes of characters only and connected by intermediate populations. This complex is also connected with other species in P. sect. Stenopoa through hybridization.

1 Lemma pubescent between veins. 77d subsp. reverdattoi

+ Lemma glabrous between veins (2)

2 (1) Panicle dense, contracted to spiciform, branches erect, the longest ones 1/5–1/3 (–2/5) as long as panicle; culm with uppermost node up to 1/6 way up culm (3)

+ Panicle usually open, especially at anthesis, longest branches 1/3–1/2 as long as panicle; culm with upper node usually ca. 1/6 way up culm (4)

3 (2) Culm under panicle usually with dense prickles. 77c subsp. orinosa

+ Culm under panicle usually with few or no prickles, usually warty. 77f subsp. ochotensis

4 (2) Ligule (3–)4–7 mm. 77e subsp. varia

+ Ligule 1–3 mm (5)

5 (4) Culm under the panicle usually with dense prickles; spikelets usually green; plants of lower and middle elevations. 77a subsp. stepposa

+ Culm under the panicle usually with few or no prickles, usually warty; spikelets usually purplish; plants of middle and upper elevations. 77b subsp. relaxa