细草 xi ge cao

Annual, tufted. Culms 20–100 cm tall. Uppermost leaf sheaths not inflated; leaf blades 3–9 mm wide; ligule 4–6 mm. Panicle dense, ovate to oblong, 1–6 cm. Spikelets elliptic, 4.5–5.5 mm; glumes winged on upper part of keel, wing margin erose-denticulate; sterile lemma 1, ca. 1 mm, appressed-pilose; fertile lemma lanceolate-ovate, 2.7–4 mm, pubescent, becoming cartilaginous and shiny. Anthers 1.5–1.8 mm. 2n = 28.

Wheat fields, introduced. Yunnan [Bhutan, N India, Pakistan; N Africa, SW Asia, S Europe].

This annual weed, native in the Mediterranean region, is now widely distributed in many parts of the world. It was introduced to China accidentally in wheat seed imported from Mexico about 1974 and is becoming naturalized in parts of Yunnan.