Bromus hordeaceus |
Bromus aleutensis |
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brome mou, lesser soft brome, lopgrass, soft brome, soft chess |
Aleut brome, Aleutian brome |
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Habit | Plants annual or biennial. | Plants perennial; loosely cespitose. | ||||||||||||
Culms | 2-70 cm, erect or ascending. |
40-130 cm tall, 3-7 mm thick, often decumbent. |
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Sheaths | coarsely striate, pilose, hairs sparse to moderately dense, throats pilose; auricles rarely present; ligules 3.5-5 mm, usually glabrous, occasionally pubescent, lacerate; blades 13-35 cm long, 6-15 mm wide, flat, usually sparsely to moderately pilose on both surfaces, sometimes glabrous. |
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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. |
10-28 cm, erect, open or somewhat contracted; lower branches to 10 cm, 1-2 per node, stiffly ascending, with (1)2-3 spikelets on the distal 72, sometimes confined to the tips. |
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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. |
25-40 mm, elliptic to lanceolate, strongly laterally compressed, with 3-6 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. |
glabrous or pubescent; lower glumes 9-13 mm, 3-5-veined; upper glumes 10-15 mm, 7(9)-veined; lemmas 12-17 mm, lanceolate, laterally compressed, usually softly pubescent, sometimes glabrous, strongly keeled at least distally, 9(11)-veined, veins conspicuous distally, apices entire or with acute teeth shorter than 1 mm; awns (3)5-10 mm; anthers 2.2-4.2 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. |
= 56. |
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Bromus hordeaceus |
Bromus aleutensis |
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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; WA; AB; BC; ON; QC |
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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 aleutensis grows in sand, gravel, and disturbed soil along the Pacific coast, from the Aleutian Islands of Alaska to western Washington, and on some lake shores of central British Columbia. It has also been found further east in Canada and in northern Idaho, always in disturbed sites, such as road edges. Bromus aleutensis might represent a modified version of B. sitchensis, in which reproduction occurs at a relatively early developmental state in response to the climatic conditions of the Aleutian Islands (Hulten 1968). B. aleutensis is predominantly self-fertilizing, and B. sitchensis is predominantly outcrossing. Anther lengths close to 4.2 mm suggest that at least some plants of B. aleutensis are outcrossing (Hitchcock 1969). Bromus aleutensis intergrades with B. carinatus var. marginatus to the south. (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. 203. | ||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Ceratochloa | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | B. mollis | B. sitchensis var. aleutensis | ||||||||||||
Name authority | L. | Trin. ex Griseb. | ||||||||||||
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