希斯肯早熟禾 xi si ken zao shu he

Arctopoa ×schischkinii (Tzvelev) Probatova.

Perennials, stoutly rhizomatous; shoots extravaginal. Culms stout, erect, simple, 25–40(–60) cm tall, 2–3 mm in diam., smooth, nodes 2 or 3, sometimes 1 exserted, base enclosed by withered fibrous sheaths. Leaf sheaths loose, smooth, 6–20 cm, several × longer than its blade, basal ones strigose near the nodes only, uppermost closed for 1/6–1/4 length; blade grayish green, flat or folded, papery, 4–20(–50) cm, 2–8 mm wide, abaxially smooth, adaxially scabrid along the prominent veins, apex slender prow-tipped; ligule white or off-white, 1.5–3 mm, abaxially scabrid, apex truncate, ciliolate, collar margins ciliolate or glabrous. Panicle open, diffuse, 10–20 × 10–15 cm; branches spreading widely, strict, 2–5 per node, stout, angular, scabrid, longest (5–)10–20 cm, branching divaricately in distal 1/2, with spikelets in distal 1/4. Spikelets oblong to lanceolate, 5–7 mm; vivipary absent; glumes narrowly to broadly lanceolate, 3–4 mm, keel scabrid, surface smooth, lower glume slightly shorter, 1(or 3)-veined, proximally ciliate or villous, distally smooth or margins scabrid; lemmas ca. 5 mm, keel and marginal veins proximally densely villous; callus glabrous; palea proximally scabrid to pilulose between keels, keels medially ciliate, pilulose or villous. Anthers ca. 2.2 mm. Fl. and fr. Jul–Aug.

Sporadic in steppe grasslands on middle to high mountains, saline wet meadows. Nei Mongol, Qinghai, Xinjiang (Altay) [Mongolia, Russia (Siberia)].

Tzvelev (Zlaki SSSR, 1976) suggested that Poa ×schischkinii is a hybrid between P. tibetica and P. subfastigiata. The sporadic occurrence of intermediate forms suggests that these may represent remnants of a series of hybrids or introgressed plants between parents that are no longer or only sporadically in contact.