Bromus hordeaceus |
Bromus pacificus |
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brome mou, lesser soft brome, lopgrass, soft brome, soft chess |
Pacific brome |
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Habit | Plants annual or biennial. | Plants perennial; not rhizomatous. | ||||||||||||
Culms | 2-70 cm, erect or ascending. |
60-170 cm, erect; nodes (5)6-8, pubescent; internodes usually glabrous, sometimes pubescent near the nodes. |
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Sheaths | pilose, midrib of the culm leaves not abruptly narrowed just below the collar; auricles absent; ligules 2-4 mm, glabrous, truncate, erose or lacerate; blades 20-35(37) mm long, 6-16 mm wide, flat, abaxial surfaces glabrous, adaxial surfaces pilose. |
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Panicles | 1-13 cm long, 1-4 cm wide, erect, usually ovoid, open, becoming dense, occasionally reduced to 1 or 2 spikelets; branches shorter than the spikelets, ascending to erect, straight or almost so. |
10-25 cm, open, nodding; branches ascending, spreading, or drooping. |
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Spikelets | (11)14-20(23) mm, lanceolate, terete to moderately laterally compressed; florets 5-10, bases concealed at maturity; rachilla internodes concealed at maturity. |
20-30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with (4)6-10 florets. |
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Glumes | pilose or glabrous; lower glumes 5-7 mm, 3-5-veined; upper glumes 6.5-8 mm, 5-7-veined; lemmas 6.5-11 mm long, 3-5 mm wide, lanceolate, chartaceous, antrorsely pilose to pubescent, or glabrous proximally or throughout, 7-9-veined, lateral veins prominently ribbed, rounded over the midvein, hyaline margins abruptly or bluntly angled, not inrolled at maturity, apices acute, bifid, teeth shorter than 1 mm; awns 6-8 mm, usually arising less than 1.5 mm below the lemma apices, straight to recurved at maturity; anthers 0.6-1.5 mm. |
pubescent; lower glumes 6-8.5 mm, 1(3)-veined; upper glumes 8-11.5 mm, 3-veined, not mucronate; lemmas 10-12 mm, lanceolate, rounded over the midvein, backs pubescent, margins more densely so, apices acute, entire; awns 3.5-7 mm, straight, arising less than 1.5 mm below the lemma apices; anthers 2-4 mm. |
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Caryopses | equaling or shorter than the paleas, thin, weakly inrolled to flat. |
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Lower | sheaths densely, often retrorsely, pilose; upper sheaths pubescent or glabrous; ligules 1-1.5 mm, hairy, obtuse, erose; blades 2-19 cm long, 1-4 mm wide, abaxial surfaces glabrous or hairy, adaxial surfaces hairy. |
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2n | = 28. |
= 28. |
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Bromus hordeaceus |
Bromus pacificus |
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Distribution |
AK; AR; AZ; CA; CO; CT; DE; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; WA; WI; WY; HI; AB; BC; LB; NB; NS; NT; ON; QC; YT; Greenland
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AK; OR; WA; BC
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Discussion | Bromus hordeaceus is native to southern Europe and northern Africa. It is weedy, growing in disturbed areas such as roadsides, fields, sandy beaches, and waste places, and can be found in many locations in the Flora region, with the exception of the central Canadian provinces and most of the southeastern United States. Its origin is obscure. Ainouche et al. (1999) reviewed various suggestions, and concluded that at least one of its diploid ancestors may have been an extinct or undiscovered species related to B. caroli-henrici, a diploid species. The four subspecies are usually morphologically distinct. Ainouche et al. (1999), however, found no evidence of genetic differentiation among them. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Bromus pacificus grows in moist thickets, openings, and ravines along the Pacific coast from southeastern Alaska to northern California, with a few occurrences further inland. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 232. | FNA vol. 24, p. 218. | ||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromopsis | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | B. mollis | Bromopsis pacifica | ||||||||||||
Name authority | L. | Shear | ||||||||||||
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