Phleum schoenoides Linnaeus, Sp. Pl. 1: 60. 1753; Heleochloa schoenoides (Linnaeus) Host.

Culms tufted, prostrate or ascending, 5–20 cm or more tall, 3–5-noded, glabrous. Leaf sheaths loose and enlarged, smooth, glabrous, shorter than internodes; leaf blades demarcated from sheath, involute, 2–10 × 0.1–0.4 cm, adaxial surface puberulent or pilose, abaxial surface glabrous or pilose, apex acicular. Inflorescence often subtended by enlarged inflated uppermost sheath, ellipsoid or ovoid, 1–3 × 0.5–1 cm, rachis distinct. Spikelets greenish or purple, 3–4 mm; glumes unequal, slightly shorter than lemma, ciliate on keel; lower glume 2.2–2.5 mm; upper glume 2.5–2.8 mm; lemma 3–3.6 mm, keel ciliolate, acute; palea slightly shorter than or equaling lemma, 2-veined. Anthers 3, 0.8–1 mm. Grain elliptic, 1–1.5 mm. Fl. and fr. Jun–Sep. 2n = 16, 18, 36.

Crypsis vaginiflora (Forsskål) Opiz is a very similar species found from Africa to India. It occurs in Kashmir and is to be expected in Xizang. It differs by its hairy leaf sheath margins and collar, subequal glumes as long as the lemma, and shorter anthers (0.6–0.7 mm).

Crypsis turkestanica Eig, from C Asia and also reported from Xinjiang, has ovoid panicles usually clearly longer than wide and supported by 2 terminal leaf sheaths, a palea with 1 or 2 inconspicuous veins, 2 or 3 stamens, and anthers 0.6–1.3 mm long.

Sandy soils, grassy roadsides. Anhui, Hebei, Henan, Jiangsu, Nei Mongol, Ningxia, Shandong, Shanxi, Xinjiang [Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan; SW Asia, S Europe, Mediterranean region; introduced in North America and isolated records elsewhere].