Bromus briziformis |
Bromus hordeaceus |
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rattlesnake brome, rattlesnake chess, rattlesnake grass |
brome mou, lesser soft brome, lopgrass, soft brome, soft chess |
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Habit | Plants annual. | Plants annual or biennial. | ||||||||||||
Culms | 20-62 cm, erect or ascending. |
2-70 cm, erect or ascending. |
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Sheaths | densely pilose; ligules 0.5-2 mm, hairy, obtuse, erose; blades 3-13 cm long, 2-4 mm wide, pilose to pubescent on both surfaces. |
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Panicles | 5-15 cm long, 3-7 cm wide, open, secund, nodding; branches sometimes longer than the spikelets, curved to reflexed. |
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. |
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Spikelets | 15-27 mm long, 8-12 mm wide, ovate, laterally compressed; florets 7-15, bases concealed at maturity; rachilla internodes concealed at maturity. |
(11)14-20(23) mm, lanceolate, terete to moderately laterally compressed; florets 5-10, bases concealed at maturity; rachilla internodes concealed at maturity. |
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Glumes | smooth or scabridulous; lower glumes 5-6 mm, 3-5-veined; upper glumes 6-8 mm, 7-9-veined; lemmas 9-10 mm long, 6-8 mm wide, inflated, obovate or rhombic, coriaceous, smooth or scabridulous, obscurely 9-veined, rounded over the midvein, margins hyaline, 1-1.3 mm wide, abruptly angled, not inrolled at maturity, apices acute to obtuse, bifid, teeth shorter than 1 mm; awns usually absent, sometimes to 1 mm, arising less than 1.5 mm below the lemma apices; anthers 0.7-1 mm. |
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. |
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Caryopses | equaling or shorter than the paleas, thin, weakly inrolled or flat. |
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 | = 14. |
= 28. |
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Bromus briziformis |
Bromus hordeaceus |
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Distribution |
AK; CA; CO; CT; DE; ID; IL; IN; MA; MD; MI; MT; ND; NE; NJ; NM; NV; NY; OH; OR; PA; SD; UT; VT; WA; WY; BC; ON
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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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Discussion | Bromus briziformis grows in waste places, road verges, and overgrazed areas. It is native to southwest Asia and Europe, and is adventive in the Flora region, occurring from southern British Columbia to as far south as New Mexico, and in scattered locations eastward. The unique shape of its spikelets has led to its use in dried flower arrangements and as a garden ornamental. The common name may refer to the similarity of the spikelets to a rattlesnake's tail. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
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Key |
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Source | FNA vol. 24, p. 228. | FNA vol. 24, p. 232. | ||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | B. brizaeformis | B. mollis | ||||||||||||
Name authority | Fisch. & C.A. Mey. | L. | ||||||||||||
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