Bromus vulgaris |
Bromus arizonicus |
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Columbia brome, Columbian brome, common brome |
Arizona brome |
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Habit | Plants perennial; not rhizomatous. | Plants annual; tufted. |
Culms | 60-120 cm, erect or spreading; nodes (3)4-6(7), usually pilose; internodes glabrous. |
30-90 cm tall, to 3 mm thick, erect. |
Sheaths | pilose or glabrous; auricles absent; ligules 2-6 mm, glabrous, obtuse or truncate, erose or lacerate; blades 13-25(33) cm long, to 14 mm wide, flat, abaxial surfaces usually glabrous, sometimes pilose, adaxial surfaces usually pilose, sometimes glabrous. |
retrorsely pilose, sometimes mostly glabrous, throats sometimes with hairs; auricles absent; ligules 1-4 mm, usually glabrous, obtuse, erose; blades 8-18 cm long, 3-9 mm wide, flat, sparsely pilose on both surfaces or the abaxial surfaces glabrous. |
Panicles | 10-15 cm, open; branches ascending to drooping. |
12-25 cm, somewhat contracted or open; lower branches shorter than 10 cm, 2-3(5) per node, initially erect to ascending, spreading at maturity, with 1-2 spikelets variously distributed. |
Spikelets | 15-30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with (3)4-9 florets. |
18-25 mm, elliptic to lanceolate, strongly laterally compressed, with 4-8 florets. |
Glumes | glabrous or pilose; lower glumes 5-8 mm, 1(3)-veined; upper glumes 8-12 mm, 3-veined; lemmas 8-15 mm, lanceolate, rounded over the midvein, backs sparsely hairy or glabrous, margins usually coarsely pubescent, sometimes glabrous, apices subulate to acute, entire; awns (4)6-12 mm, straight, arising less than 1.5 mm below the lemma apices; anthers 2-4 mm. |
subequal, smooth or scabrous; lower glumes 8-12.5 mm, 3-veined; upper glumes 9.5-14 mm, 7-veined, about as long as the lowest lemma; lemmas 9.5-14 mm, lanceolate, laterally compressed, prominently 7-veined, strongly keeled at least distally, glabrous or pubescent distally or throughout, marginal hairs, if present, longer than those elsewhere, apices entire or with acute teeth shorter than 1 mm; awns 6-13 mm, sometimes slightly geniculate; anthers 0.4-0.5 mm. |
2n | = 14. |
= 84. |
Bromus vulgaris |
Bromus arizonicus |
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Distribution |
CA; ID; MT; NV; OR; UT; WA; WY; AB; BC
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AZ; CA; NV; TX
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Discussion | Bromus vulgaris grows in shaded or partially shaded, often damp, coniferous forests along the coast, and inland in montane pine, spruce, fir, and aspen forests, from sea level to about 2000 m. Its range extends from coastal British Columbia eastward to southwestern Alberta and southward to central California, northern Utah, and western Wyoming. Varieties have been described within Bromus vulgaris; because their variation is overlapping, none are recognized here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Bromus arizonicus grows in dry, open areas and disturbed ground of the southwest, usually below 2000 m. Its range extends from California and southern Nevada into Arizona, New Mexico, and northern Mexico. Stebbins et al. (1944) demonstrated that, like Bromus carinatus var. carinatus, B. arizonicus obtained three of its genomes from B. catharticus or a close relative, but the remaining three genomes are not homologous with those in B. carinatus, probably being derived from a species in a section other than Ceratochloa. The small anthers of B. arizonicus strongly suggest that most seed is produced by selfing. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 216. | FNA vol. 24, p. 201. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromopsis | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Ceratochloa |
Sibling taxa | ||
Synonyms | B. ciliatus var. glaberrimus | B. berteroanus var. excelsus |
Name authority | (Hook.) Shear | (Shear) Stebbins |
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