Plants annual; often tufted. Culms 30-60 cm, slender. Sheaths pilose-pubescent to nearly glabrous; blades 7-28 cm long, 2-9 mm wide, pilose or glabrous. Panicles 10-20 cm long, 3-9 cm wide, erect, dense; branches appressed to spreading, sometimes flexuous. Spikelets 15-20 mm, elliptic to lanceolate, more or less terete, with 3-9 florets. Glumes glabrous, acuminate; lower glumes 8-10 mm, 1-veined; upper glumes 12-16 mm, 3(5)-veined; lemmas 11-14 mm, lanceolate to linear-lanceolate, sparsely pubescent, 5-veined, rounded over the midvein, apices acuminate, bifid, teeth 2-3 mm, usually aristate, sometimes acuminate; awns 13-20 mm, geniculate, strongly to moderately twisted in the basal portion, arising 1.5 mm or more below the lemma apices; anthers 2-2.5 mm. 2n = unknown.

Bromus berteroanus is from Chile, and is now established in dry areas of western North America, including Montana, California, Nevada, Arizona, southwestern Utah, and Baja California, Mexico.

Common Name: Chilean chess

Duration: Annual

Nativity: Non-Native

Lifeform: Graminoid

General: Introduced, tufted annual 30-60 cm tall, slender.

Vegetative: Sheaths pilose-pubescent to nearly glabrous, blades 7-28 cm long, 2-9 mm wide, pilose or glabrous.

Inflorescence: Panicles 10-20 cm long, 3-9 cm wide, erect, dense; branches appressed to spreading, sometimes flexuous; spikelets 15-20 mm, elliptic to lanceolate, terete, with 3-9 florets; glabrous, acuminate glumes; lower glumes 8-10 mm, 1-veined, upper glumes 12-16 mm, 3-5 veined; lemmas 11-14 mm, lanceolate to linear-lanceolate, sparsely pubescent, 5-veined, rounded over midvein, acuminate apices, bifid, teeth 2-3 mm, awns 13-20 mm, geniculate, strongly to moderately twisted in basal portion, arising 1.5 mm or more below the lemma apices.

Ecology: Found in dry areas, slopes from sea level to 3,000 ft (914 m); flowers February-June.

Distribution: Originally from Chile, established in dry parts of North America, generally across the interior desert west and south into northern Mexico and Baja California.

Notes: Found at a variety of elevations in Arizona. Difficult to ascertain its precise elevation range due to the spotty nature of its prior sampling.

Ethnobotany: Unknown

Etymology: Bromus is from Greek bromo, for stinking, while berteroanus is named for Carlo Giuseppe Bertero (1789-1831), an Italian physician.

Synonyms: Bromus berterianus, B. trinii, B. trinii var. excelsus, Trisetobromus hirtus

Editor: SBuckley, 2010