Bromus arizonicus |
Bromus arvensis |
|
---|---|---|
Arizona brome |
field brome, soft brome |
|
Habit | Plants annual; tufted. | Plants annual. |
Culms | 30-90 cm tall, to 3 mm thick, erect. |
80-110 cm, erect. |
Sheaths | 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 | 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. |
11-30 cm long, 4-20 cm wide, open, erect or nodding; branches usually longer than the spikelets, ascending to widely spreading, slender, slightly curved or straight. |
Spikelets | 18-25 mm, elliptic to lanceolate, strongly laterally compressed, with 4-8 florets. |
10-25 mm, lanceolate, terete to moderately laterally compressed, often purple-tinged; florets 4-10, bases concealed or visible at maturity; rachilla internodes concealed or visible at maturity. |
Glumes | 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. |
glabrous; lower glumes 4-6 mm, 3-veined; upper glumes 5-8 mm, 5-veined; lemmas 7-9 mm long, 1.1-1.5 mm wide, lanceolate, obscurely 7-veined, rounded over the midvein, glabrous, coriaceous, margins slightly angled, inrolled or not at maturity, apices acute, bifid, teeth shorter than 1 mm; awns 6-11 mm, straight, arising at varying distances below the lemma apices; anthers 2.5-5 mm. |
Caryopses | shorter than the paleas, weakly to strongly inrolled. |
|
Lower | sheaths with dense, soft, appressed hairs; ligules 1-1.5 mm, hairy, obtuse, erose; blades 10-20 cm long, 2-6 mm wide, coarsely pilose on both surfaces. |
|
2n | = 84. |
= 14. |
Bromus arizonicus |
Bromus arvensis |
|
Distribution |
AZ; CA; NV; TX
|
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; ON; QC; SK
|
Discussion | 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.) |
Bromus arvensis grows along roadsides and in fields and waste places at scattered locations in the Flora region. It is native to southern and south-central Europe. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 201. | FNA vol. 24, p. 228. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Ceratochloa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus |
Sibling taxa | ||
Synonyms | B. berteroanus var. excelsus | |
Name authority | (Shear) Stebbins | L. |
Web links |
|