Bromus polyanthus

Scribn.
Common names: Colorado brome Great-basin brome
Endemic
Synonyms: Ceratochloa polyantha
Treatment appears in FNA Volume 24. Treatment on page 205.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants perennial; loosely cespitose. Culms 60-120 cm tall, to 3 mm thick, erect, glabrous or puberulent. Sheaths usually smooth or scabrous, sometimes hairy except at the throat; auricles absent; ligules (1) 2-2.5 mm, glabrous, obtuse, erose; blades 10-31 cm long, 2-9 mm wide, flat, sometimes scabrous, usually glabrous, rarely puberulent to pubescent near the collar. Panicles 10-20 cm, open to somewhat contracted; lower branches shorter than 10 cm, (1) 2-3 per node, erect, ascending or spreading, with 1-2 spikelets variously distributed. Spikelets 20-35 mm, shorter than at least some pedicels and branches, elliptic to lanceolate, strongly laterally compressed, not crowded or overlapping, with 6-11 florets. Glumes smooth or scabrous; lower glumes (5.5) 7-10 (11.5) mm, 3-veined; upper glumes (7.5) 9-11 (12.5) mm, 5-7-veined, shorter than the lowest lemma; lemmas 12-15 mm, lanceolate, laterally compressed, strongly keeled at least distally, glabrous, sometimes scabrous, 7-9-veined, veins usually not raised or riblike, apices entire or with acute teeth, teeth shorter than 1 mm; awns 4-7 mm; anthers 1-5 mm. 2n = 56.

Distribution

Mont., Oreg., Colo., N.Mex., Ariz., Calif., Idaho, Nev., Tex., Utah, Wash., Wyo., B.C.

Discussion

Bromus polyanthus grows on open slopes and in meadows. It is found primarily in the central Rocky Mountains, but the limits of its range include British Columbia in the north, California in the west, and Arizona, New Mexico, and western Texas in the south. It is not known from Mexico. It intergrades with B. carinatus var. marginatus. Plants with an erect, contracted panicle and awns 4-6 mm long can be called B. polyanthus var. polyanthus; those with with an open, nodding panicle and awns up to 8 mm long can be called B. polyanthus var. paniculatus Shear. Because the variation in both characters is continuous, the varieties are not recognized here.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Bromus polyanthus"
membranous +  and scarious +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
with acute teeth +  and entire +
Leon E. Pavlickf +
Scribn. +
divaricate +
1 (?) +  and 3 (?) +
straight +
distinct +
subterminal +  and terminal +
geniculate +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
10 cm100 mm <br />0.1 m <br /> (31 cm310 mm <br />0.31 m <br />) +
not evident +
rarely puberulent +  and pubescent +
cross +, linear +  and narrowly lanceolate +
2mm;9mm +
drooping;reflexed;usually ascending;spreading +
spikelike +
Colorado brome +  and Great-basin brome +
not branching +
60 cm600 mm <br />0.6 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
puberulent +  and glabrous +
5 cm50 mm <br />0.05 m <br /> (190 cm1,900 mm <br />1.9 m <br />) +
not woody +
0 cm0 mm <br />0 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Mont. +, Oreg. +, Colo. +, N.Mex. +, Ariz. +, Calif. +, Idaho +, Nev. +, Tex. +, Utah +, Wash. +, Wyo. +  and B.C. +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
6 +  and 11 +
terete +  and laterally compressed +
1-9(11)-veined +
always shorter +  and usually shorter +
lanceolate +
subtending +
pubescent +  and glabrous +
mucronate +  and acute +
unequal +
uncinate +
solid +  and hollow +
keeled +, compressed +  and lanceolate +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
herbaceous +  and coriaceous +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
spreading +, ascending +  and erect +
10 cm100 mm <br />0.1 m <br /> (?) +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
concealed +  and prominent +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
reduced +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
dry +  and fleshy +
hairy +, scabrous +  and smooth +
overlapping +, not crowded +  and distributed +
not viviparous +
compressed +, elliptic +  and lanceolate +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Ceratochloa polyantha +
Bromus polyanthus +
Bromus sect. Ceratochloa +
species +
membranous +
1 cm10 mm <br />0.01 m <br /> (?) +
0.9 cm9 mm <br />0.009 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
plant +  and cespitose +
aquatic +  and terrestrial +