Bromus diandrus |
Bromus porteri |
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great brome, ripgut brome, ripgut grass |
nodding brome, Porter brome, Porter's brome |
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Habit | Plants annual. | Plants perennial; not rhizomatous. |
Culms | 20-90 cm, erect or decumbent, puberulent below the panicle. |
30-100 cm, erect; nodes (2)3-4(5), glabrous or pubescent; internodes mostly glabrous, puberulent near 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 or pilose, midrib of the culm leaves not abruptly narrowed just below the collar; auricles absent; ligules to 2.5 mm, glabrous, truncate or obtuse, erose or lacerate; blades (3)10-25(35) cm long, 2-5(6) mm wide, flat, not glaucous, both surfaces usually glabrous, sometimes the adaxial surface pilose. |
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. |
7-20 cm, open, nodding, often 1-sided; branches slender, ascending to spreading, often recurved and flexuous. |
Spikelets | 25-70 mm, sides parallel or diverging distally, moderately laterally compressed, with 4-11 florets. |
12-38 mm, elliptic to lanceolate, terete to moderately laterally compressed, with (3)5-11(13) 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. |
usually pubescent, rarely glabrous; lower glumes 5-7(9) mm, usually 3-veined, sometimes 1-veined; upper glumes 6-10 mm, 3-veined, not mucronate; lemmas 8-14 mm, elliptic, rounded over the midvein, usually pubescent or pilose, margins often with longer hairs, backs and margins rarely glabrous, apices acute or obtuse to truncate, entire; awns (1)2-3(3.5) mm, straight, arising less than 1.5 mm below the lemma apices; anthers (1)2-3 mm. |
2n | = 42, 56. |
= 14. |
Bromus diandrus |
Bromus porteri |
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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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AZ; CA; CO; ID; MT; ND; NE; NM; NV; SD; TX; UT; WY; MB; SK
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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 porteri grows in montane meadows, grassy slopes, mesic steppes, forest edges, and open forest habitats, at 500-3500 m. It is found from British Columbia to Manitoba, and south to California, western Texas, and Mexico. It is closely related to B. anomalus, and has often been included in that species. It differs chiefly in its lack of auricles, and in having culm leaves with midribs that are not narrowed just below the collar. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 224. | FNA vol. 24, p. 213. |
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 | Bromopsis ported |
Name authority | Roth | (J.M. Coult.) Nash |
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