6. Poa bulbosa Linnaeus, Sp. Pl. 1: 70. 1753.
鳞茎早熟禾 lin jing zao shu he
Perennials, densely tufted; shoots with bulbous bases. Culms erect or geniculately ascending, (9–)15–55 cm tall, base with bulbous withered leaf sheaths, nodes 2 or 3, exserted. Leaf sheath smooth, uppermost culm sheath closed for 1/4 of length, tiller sheaths usually less than 1/15–1/7(–1/5) length of blades; blades flat or folded, thin, soon withering, mostly basal, 2–10 cm, 0.5–2(–2.5) mm wide, surfaces smooth, margins scabrid, not cartilaginous; ligule hyaline or milky-white, 1–2(–3.5) mm, apex acuminate. Panicle contracted (looser in viviparous inflorescences), oblong to ovate, 2–8 cm; branches obliquely ascending, 2–4 per node, scabrid, longest to 2 cm. Spikelets purple tinged, 3.5–5(–7.5) mm, florets 2–6 (when normal); vivipary commonly present; rachilla smooth, glabrous; glumes subequal, ovate, 3-veined, 2–3 mm, keel sparsely scabrid; lemmas normal or viviparous, lower 1 or 2 normal, (2.5–)3–3.5 mm, apex acute, keel villous to 2/3 of length, marginal veins to 1/2, area between veins glabrous, often glabrous throughout in viviparous spikelets; callus webbed, hairs moderately dense, commonly glabrous in viviparous spikelets; palea keels scabrid. Anthers (1–)1.4–1.6 mm, usually abortive in viviparous spikelets. Fl. and fr. May–Jul. 2n = 14, 28, 39, 42, 45.
Plains, sandstone slopes, desert grasslands, river shores, wastelands near fruit gardens; 700–4700 m. Xinjiang, Xizang [Afghanistan, NW India, Kazakhstan, Kyrgyzstan, Nepal, Pakistan, Russia (Siberia), Tajikistan, Turkmenistan, Uzbekistan; Africa, SW Asia, Europe; introduced in Australia, New Zealand, North and South America, and Pacific Islands].
This widespread and weedy species is probably introduced in China. It is a useful spring forage. It is readily recognizable by the bulbous sheathed bases of the shoots and common occurrence of vivipary. FRPS (9(2): 212. 2002) reported viviparous material of Poa sinaica Steudel from Qinghai and Xinjiang, but this normally non-viviparous species is unlikly to be present in China. It occurs from SW Asia to Afghanistan and W Pakistan. Normal-flowered material is needed to see the key distinctions of lemma length (3.5–4.5 mm) and glabrous calluses. The Chinese material seems a better match for P. bulbosa, and we conclude that P. sinaica does not occur in China.