Bromus rigidus Roth in Roemer & Usr., Mag. Bot. 10: 21. 1790. Hitchc., Man. Grass. U. S. 52. f. 36. 1951; Keng, Fl. Ill. Pl. Prim. Sinicarum Gram. 275. f. 223. 1959; Kuo. Taiwania 24: 22. 1979; Koyama, Grass. Jap. Neighb. Reg. 43. 1987; Osada, Ill. Grasses Jap. Enl. Ed. 382. 1993.
Bromus diandrus Roth, Bot. Abh. 44. 1787; Veldkamp, Blumea 35(2): 489. 1991.
Annuals, or biennials. Culms ascending, 30-70 cm tall, 3.5 mm wide. Leaf-blades chartaceous, linear, 5-18 cm long, 2-5.5 mm wide, sharp at apex, veins conspicuous, puberulous above, villous beneath. Sheath loosely villous. Ligule membranous, tongue-shaped, rounded at apex, 3 mm long. Inflorescence an open panicle, 7-20 cm long. Spikelets with 4-8 florets, elliptical, 45 mm long, 4 mm wide, slightly laterally compressed. Pedicels minutely hispid. Lower glumes chartaceous, glabrous or loosely strigose, linear-lanceolate, sharp at apex, 20 mm long, 1 -nerved. Upper glumes subcoriaceous, lanceolate, sharp at apex, 15-30 mm long, longer than 10 mm, 3 -nerved, minutely strigose. Florets 22-32 mm long, with rachilla. Lemmas subcoriaceous, lanceolate, margins inrolled, shortly bilobed at apex, 22-32 mm long, longer than 20 mm, with awn, with a awn longer than lemma, 5-7 -nerved, hairy, densely pubescent on back surface. Paleas membranous, linear oblong, round or truncate at apex, 12-16 mm long, 2 -nerved, ciliate on nerves. Callus glabrous. Anthers 2 mm long. Caryopsis linear-oblong, 10 mm long, hilum linear.
TAICHUNG: Anmasshan forest trail 43K, Kuo 9611 .
Native to the Mediterranean region of Europe, widely naturalized in North Hemisphere.
First collected in Taiwan at Anmashan in 1978.