鸭茅 ya mao

Dactylis altaica Besser; D. glomerata subsp. altaica (Besser) Domin; D. glomerata var. altaica (Besser) Keng; D. glom-erata subsp. sinensis A. Camus; D. glomerata subsp. himalay-ensis Domin.

Perennial, coarse. Culms solitary or tufted, erect or geniculate at base, 40–140 cm tall. Leaf sheaths strongly keeled; leaf blades flat, (6–)10–30 cm × 4–9 mm, abaxial surface scabrid along midrib and margin; ligule 4–8 mm. Panicle oblong to ovate in outline, 5–15 cm; branches single or rarely paired at base, (3–)5–15 cm, horizontal or ascending, lower part naked, upper part with dense fascicles of spikelets. Spikelets oblong to wedge-shaped, 5–9 mm, florets closely overlapping, green or purplish; glumes 4–5(–6.5) mm, scabrid or ciliolate along keel, margins membranous, apex acute to acuminate; lemmas 4–7 mm, lowest subequal to spikelet, scabrid or flanks short-pilose, apex with stout awn up to 1.5 mm. Anthers ca. 2.5 mm. Fl. and fr. May–Aug. 2n = 14, 28, 42.

Mountain slopes, light forest shade, other grassy places; 1400–3600 m. Gansu, Guizhou, Hubei, Ningxia, Shaanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang; cultivated in Hebei, Henan, Jiangsu, Shandong [Bhutan, N India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Russia, Tajikistan, Turkestan, Uzbekistan; N Africa, SW Asia, Europe].

This is an important pasture and forage grass that has been widely introduced into temperate and subtropical regions throughout the world (Cocksfoot, Orchard Grass).

The typical form, subsp. glomerata (2n = 28), has a relatively compact panicle, broad spikelet fascicles, and conspicuously ciliate lemma keels. Other forms, widespread in China and the Himalayas, have a looser panicle with long flexuose branches, narrower spikelet fascicles, and only minutely ciliolate lemma keels. The names subsp. sinensis, subsp. himalayensis, and the European name subsp. slovenica (Domin) Domin have been applied to these forms. A chromosome count of 2n = 14 has been recorded for subsp. himalayensis. The basis of this variation, the correct application of these names, and their relationship to similar variants from outside China are not yet understood.