Plants perennial; not rhizomatous. Culms 40-90 cm, erect; nodes (3)4-7(8), these and the internodes pubescent or glabrous. Sheaths glabrous or pilose, midrib of the culm leaves abruptly narrowed just below the collar; auricles often present on the lower leaves; ligules to 1 mm, truncate; blades 14-22(26) cm long, to 6 mm wide, flat, glabrous or pilose, not glaucous. Panicles 10-20 cm, open, nodding; branches ascending or spreading. Spikelets (14)15-30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with 4-12 florets. Glumes usually pubescent, rarely glabrous; lower glumes 5-6 mm, 1-3-veined; upper glumes 6-8 mm, 3-veined, sometimes mucronate; lemmas 7-10 mm, elliptic to lanceolate, rounded over the midvein, backs and margins pubescent, apices acute to obtuse, entire; awns 1-3(5) mm, straight, arising less than 1.5 mm below the lemma apices; anthers 2-4 mm. 2n = 14.

Bromus anomalus grows on rocky slopes in western Texas and adjacent Mexico. Many records of this species in the Flora region are here treated as B. porteri, a closely related species that has sometimes been included in B. anomalus. The two differ mainly in B. anomalus having culm leaves with midribs that are narrowed just below the collar, as well as auricles.

FNA 2007, Gould 1980

Common Name: nodding brome Duration: Perennial Nativity: Native Lifeform: Graminoid General: Non-rhizomatous perennial with slender erect stems 40-90 cm, with 4-7 nodes, these and internodes pubescent to glabrous; sheaths pilose or glabrous, midrib of stem leaves narrow abruptly below collar, auricle on lower leaves. Vegetative: Blades narrow, 14-22 cm long, to 6 mm wide, flat, glabrous or pilose, dull bluish green; ligules to 1 mm truncate. Inflorescence: Open, nodding panicle 10-20 cm with slender, drooping few-flowered branches, with spikelets 15-30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with 4-12 florets; glumes pubescent, rarely glabrous, subequal, lower 5-6 mm, 1-3 veined, upper 6-8 mm, 3-veined, sometimes mucronate; lemmas thin, elliptic to lanceolate, 7-10 mm, backs and margins pubescent, apices acute to obtuse, entire with straight awns, arising less than 1.5 mm below the lemma apices. Ecology: Found on rocky slopes in woodlands and forested areas from 2,000-5,000 ft (610-1524 m); flowers June-October. Notes: Distinguished by the the more or less uniform pubescence on the back of the lemmas, the few flowered panicle, and the dull bluish green colored blades. Barksworth et al. indicate this grass as only existing in western Texas and Mexico, all these specimens have been located in Bromus porteri. The main difference is that B. anomalous has auricles and the stem leaves are narrowed below the collar. Ethnobotany: Used for fodder. Etymology: Bromus is from Greek bromo, for stinking, while anomalus means unusual. Synonyms: Bromopsis anomala, Bromus ciliatus var. minor Editor: SBuckley, 2010