Bromus diandrus |
Bromus suksdorfii |
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great brome, ripgut brome, ripgut grass |
Suksdorf's brome, Suksdorf's bromegrass |
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Habit | Plants annual. | Plants perennial; not rhizomatous. |
Culms | 20-90 cm, erect or decumbent, puberulent below the panicle. |
50-100 cm, erect; nodes 2-3(4), glabrous, internodes glabrous or puberulent just below the nodes. |
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. |
glabrous; auricles absent; ligules to 1 mm, glabrous, truncate; blades (8)12-19(24) cm long, 4-8(14) mm wide, flat, glabrous, margins scabrous. |
Panicles | 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. |
6-14 cm, erect, contracted; branches erect or ascending. |
Spikelets | 25-70 mm, sides parallel or diverging distally, moderately laterally compressed, with 4-11 florets. |
15-30 mm, elliptic to lanceolate, terete to moderately laterally compressed, with (3)5-7 florets. |
Glumes | 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. |
glabrous or sparsely pubescent; lower glumes 7-11 mm, 1(3)-veined; upper glumes 9-12 mm, 3-veined; lemmas 12-15 mm, elliptic, rounded over the midvein, backs and margins pubescent or nearly glabrous, apices obtuse, entire; awns 2-5 mm, straight, arising less than 1.5 mm below the lemma apices; anthers 2-3.5 mm. |
2n | = 42, 56. |
= 14. |
Bromus diandrus |
Bromus suksdorfii |
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Distribution |
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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CA; ID; NV; OR; WA
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Discussion | 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.) |
Bromus suksdorfii grows on open slopes and in open subalpine forests, at about 1300-3300 m, from southern Washington to southern California. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 224. | FNA vol. 24, p. 218. |
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Genea | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromopsis |
Sibling taxa | ||
Synonyms | B. rigidus var. gussonei, B. rigidus, Anisantha diandra | |
Name authority | Roth | Vasey |
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