Bromus racemosus |
Bromus diandrus |
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bald brome, brome a grappes, smooth brome |
great brome, ripgut brome, ripgut grass |
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Habit | Plants annual. | Plants annual. |
Culms | 20-110 cm, erect or ascending. |
20-90 cm, erect or decumbent, puberulent below the panicle. |
Sheaths | softly pilose, hairs often retrorse or spreading; auricles absent; ligules 2-3 mm, glabrous, obtuse, lacerate or erose; blades 3.5-27 cm long, 1-9 mm wide, both surfaces pilose. |
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Panicles | 4-16 cm long, 2-3 cm wide, erect, open; branches sometimes longer than the spikelets, slender, usually ascending, slightly curved or straight. |
13-25 cm long, 2-12 cm wide, erect to spreading; branches 1-7 cm, stiffly erect to ascending or spreading, with 1 or 2 spikelets. |
Spikelets | 12-20 mm, lanceolate, terete to moderately laterally compressed; florets 5-6, bases concealed at maturity; rachilla internodes 1-1.5 mm, concealed at maturity. |
25-70 mm, sides parallel or diverging distally, moderately laterally compressed, with 4-11 florets. |
Glumes | smooth to scabrous; lower glumes 4-6 mm, (3)5-veined; upper glumes 4-7 mm, 7-veined; lemmas 6.5-8 mm long, 3-4.5 mm wide, elliptic to lanceolate, coriaceous, backs smooth, distinctly 7(9)-veined, not ribbed, rounded over the midvein, margins scabrous, rounded, not inrolled at maturity, apices acute to obtuse, bifid, teeth shorter than 1 mm; awns 5-9 mm, all more or less equal in length, straight, arising less than 1.5 mm below the lemma apices; anthers 1.5-3 mm. |
smooth or scabrous, margins hyaline; lower glumes 15-25 mm, 1-3-veined; upper glumes 20-35 mm, 3-5-veined; lemmas 20-35 mm, linear-lanceolate, scabrous, 7-veined, rounded over the midvein, margins hyaline, apices bifid, acuminate, teeth 3-5 mm; awns 30-65 mm, straight, arising 1.5 mm or more below the lemma apices; anthers 0.5-1 mm. |
Caryopses | shorter than the paleas, thin, weakly inrolled or flat. |
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Lower | sheaths densely hairy, hairs stiff, often retrorse; upper sheaths glabrous or pubescent; ligules 1-2 mm, glabrous or hairy, erose; blades 7-18 cm long, 1-4 mm wide, pilose on both surfaces. |
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2n | = 28. |
= 42, 56. |
Bromus racemosus |
Bromus diandrus |
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Distribution |
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; LB; NB; NS; NT; ON; PE; QC; SK
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AR; AZ; CA; CO; DC; DE; GA; ID; IL; LA; MA; MD; MO; MT; NC; NJ; NM; NV; NY; OK; OR; SC; TX; UT; VA; WA; HI; BC
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Discussion | Bromus racemosus grows in fields, waste places, and road verges. It is native to western Europe and the Baltic region, and occurs throughout much of southern Canada and the United States. Hitchcock (1951) included B. hordeaceus subsp. pseudothominei in B. racemosus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Bromus diandrus is native to southern and western Europe. It is now established in North America, where it grows in disturbed ground, waste places, fields, sand dunes, and limestone areas. It occurs from southwestern British Columbia to Baja California, Mexico, and eastward to Montana, Colorado, Texas, and scattered locations in the eastern United States. The common name 'ripgut grass' indicates the effect it has on animals if they consume the sharp, long-awned florets of this species. Bromus diandrus, as treated here, includes B. rigidus Roth. Sales (1993) reduced these two taxa to varietal rank, pointing out that the differences between them in panicle morphology and callus and scar shape are subtle enough that identification of many specimens beyond B. diandrus sensu lato is often impossible. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 233. | FNA vol. 24, p. 224. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Genea |
Sibling taxa | ||
Synonyms | B. rigidus var. gussonei, B. rigidus, Anisantha diandra | |
Name authority | L. | Roth |
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