Description from Flora of China
Culms hollow, 60–130(–150) cm tall, ca. 5-noded; nodes glabrous. Leaf blade flat, 10–24 × 0.4–1.5 cm, usually glabrous. Spike lax or dense, usually narrowed distally, square or subsquare in cross section, 5–18 cm, with up to 29 spikelets; rachis disarticulating or tough and not disarticulating, margin ciliate; internodes 3–4 mm. Spikelets with 4–9 florets (distal florets sterile). Glumes laxly appressed or adnate to floret, ovate or elliptic, sometimes very hard, distinctly or indistinctly to obscurely keeled, pubescent or glabrous; keel sometimes prolonged at apex into shortish tooth; tooth apex subobtuse, acute, or tapering into short awn. Lemma oblong-lanceolate, pubescent or glabrous, awnless to long awned; awn usually divergent. Palea subequaling lemma. Anthers yellow or purplish. Caryopsis usually free from lemma and palea. Fl. and fr. Apr–Aug.
Commonly cultivated, e.g., in fields of Hordeum and Triticum; below 3500 m. Throughout China [cultivated worldwide].