Bromus diandrus |
Bromus richardsonii |
|
---|---|---|
great brome, ripgut brome, ripgut grass |
fringe brome, Richardson's brome |
|
Habit | Plants annual. | Plants perennial; not rhizomatous. |
Culms | 20-90 cm, erect or decumbent, puberulent below the panicle. |
50-110(145) cm, erect to spreading; nodes (3)4-5(6), usually glabrous, sometimes pubescent; internodes usually glabrous. |
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. |
|
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. |
10-20(25) cm, open, nodding; branches ascending to spreading or drooping, filiform. |
Spikelets | 25-70 mm, sides parallel or diverging distally, moderately laterally compressed, with 4-11 florets. |
15-25(40) mm, elliptic to lanceolate, terete to moderately laterally compressed, with (4)6-10(15) 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 glabrous, sometimes pubescent; lower glumes 7.5-12.5 mm, 1(3)-veined; upper glumes 8.9-11.3 mm, 3-veined, often mucronate; lemmas 9-14(16) mm, elliptic, rounded over the midvein, margins more or less densely pilose on the lower 1/2 or 3/4, lower lemmas in a spikelet glabrous across the backs, uppermost lemmas with appressed hairs on the backs, apices obtuse, entire; awns (2)3-5 mm, straight, arising less than 1.5 mm below the lemma apices; anthers 1.6-2.7 mm. |
Basal | sheaths often retrorsely pilose; culm sheaths glabrous, often tufted-pilose near the auricle position, midrib of the culm leaves not abruptly narrowed just below the collar; auricles absent; ligules 0.4-2 mm, glabrous, rounded, erose, ciliolate; blades 10-35 cm long, 3-12 mm wide, flat, glabrous. |
|
2n | = 42, 56. |
= 28. |
Bromus diandrus |
Bromus richardsonii |
|
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
|
|
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 richardsonii grows in meadows and open woods in the upper montane and subalpine zones, at 2000-4000 m in the southern Rocky Mountains, and at lower elevations northwards. Its range extends from southern Alaska to southern California and northern Baja California, Mexico; it is found as far east as Saskatchewan, South Dakota, and western Texas. Specimens with pubescent nodes and glumes are apparently confined to the southwestern United States. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 24, p. 224. | FNA vol. 24, p. 222. |
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 | Bromposis richardsonii, Bromopsis canadensis subsp. ricbardsonii |
Name authority | Roth | Link |
Web links |
|