21d. Poa pratensis subsp. pruinosa (Korotky) Dickoré, Stapfia. 39: 173. 1995.
粉绿早熟禾 fen lü zao shu he
Poa pruinosa Korotky, Repert. Spec. Nov. Regni Veg. 13: 291. 1914; P. grisea Korotky; P. macrocalyx var. tianschanica Regel; P. markgrafii H. Hartmann; P. pachyantha Keng ex Shan Chen; P. pamirica Roshevitz ex Ovczinnikov; P. tians-chanica (Regel) Hackel ex O. Fedtschenko.
Plants grayish green, loosely tufted, not forming turf; shoots mainly extravaginal, often curved upward. Culms often decumbent, 15–70 cm tall, solitary or infrequently few per tuft, 1–2 mm in diam., nodes 2 or 3, uppermost node less than 1/3 way up. Blades flat or usually folded with margins inrolled, moderately papery to thickly papery, 2–5 mm wide, of tillers folded, thickly papery and firm, usually distinctly curved, 3–10(–18) cm × (1–)2–5 mm, often adaxially sparsely pubescent; ligule 0.5–4 mm, abaxially scabrid (rarely smooth). Panicle usually loosely contracted, oblong to pyramidal, somewhat lax, 4–10(–15) cm; branches ascending to spreading, (1–)2–5(–7) per node, smooth or distally scabrid, longest with spikelets in distal 1/3–1/2. Spikelets usually grayish and purple tinged, 3–6(–7) mm, florets 2–5(–7); lower glume 2.5–3.5 mm, 1- or 3-veined, upper glume 3–4 mm, 3-veined; lemmas ovate to lanceolate, 3–4.5 mm, apex acute, keel villous for 2/3 of length, marginal veins for 1/2; palea keels scabrid, glabrous or infrequently medially pilulose. Anthers 2–2.5 mm. Fl. and fr. Jun–Sep. 2n = 42.
Mountains, moist weakly saline or alkaline grassy places, alpine river banks, marshy grasslands in the north. Gansu, Heilongjiang, Qinghai, Sichuan, Xinjiang, Xizang, Yunnan [Afghanistan, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia (Siberia), Tajikistan].
This race is native to China. The inclusion of Poa tianschanica s.s. needs further study. Poa pruinosa s.s. (including P. grisea) includes plants from E Siberia with a profuse, waxy bloom and culms strongly flattened at the base. The types of P. markgrafii and P. pamirica seem typical of the subspecies. Plants without a waxy bloom, with stiff culms that are weakly flattened at base, occurring from the Altai, Khakass, and Tuva in Siberia southward through C Asia, are sometimes distinguished as P. tianschanica s.s. Tzvelev (Zlaki SSSR, 459. 1976) treated these as one species, possibly derived from hybridization between P. pratensis and P. tibetica. Poa pachyantha seems to fit within P. pratensis subsp. pruinosa; although the culms are not flattened, the lower sheaths are flattened and somewhat keeled, and the plants are gray with anthocyanic spikelets that are somewhat clustered. Poa sabulosa (Turczaninow ex Roshevitz) Turczaninow ex Roshevitz was reported in FRPS (9(2): 102. 2002) from Heilongjiang, in low, wet, sandy places by river banks, lake shores, seashores, and saline meadows. No voucher was seen, and it is doubtfully present in China. In Russia it is considered a narrow endemic of subsaline meadows in the Baikal region of Siberia and N Mongolia, and is treated as a low-growing (10–30 cm), small-spikeleted (lemmas 2.3–2.8 mm) race, as P. pratensis subsp. sabulosa (Turczaninow ex Roshevitz) Tzvelev, or lumped within P. pratensis subsp. pruinosa s.l.