Bromus tectorum

L.
Common names: Cheatgrass Downy chess
Introduced
Synonyms: Bromus tectorum var. nudus Bromus tectorum var. glabratus Anisantha tectorum
Treatment appears in FNA Volume 24. Treatment on page 226.
Please click on the illustration for a higher resolution version.
Illustrator: Cindy Roché

Copyright: Utah State University

Plants annual. Culms 5-90 cm, erect, slender, puberulent below the panicle. Sheaths usually densely and softly retrorsely pubescent to pilose, upper sheaths sometimes glabrous; auricles absent; ligules 2-3 mm, glabrous, obtuse, lacerate; blades to 16 cm long, 1-6 mm wide, both surfaces softly hairy. Panicles 5-20 cm long, 3-8 cm wide, open, lax, drooping distally, usually 1-sided; branches 1-4 cm, drooping, usually 1-sided and longer than the spikelets, usually at least 1 branch with 4-8 spikelets. Spikelets 10-20 mm, usually shorter than the panicle branches, sides parallel or diverging distally, moderately laterally compressed, often purplish-tinged, not densely crowded, with 4-8 florets. Glumes villous, pubescent, or glabrous, margins hyaline; lower glumes 4-9 mm, 1-veined; upper glumes 7-13 mm, 3-5-veined; lemmas 9-12 mm, lanceolate, glabrous or pubescent to pilose, 5-7-veined, rounded over the midvein, margins hyaline, often with some hairs longer than those on the backs, apices acuminate, hyaline, bifid, teeth 0.8-2 (3) mm; awns 10-18 mm, straight, arising 1.5 mm or more below the lemma apices; anthers 0.5-1 mm. 2n = 14.

Distribution

Conn., N.J., N.Y., Wash., Del., D.C., Wis., W.Va., Pacific Islands (Hawaii), Mass., Maine, N.H., R.I., Vt., Fla., Wyo., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., Calif., Nev., Va., Colo., Alaska, Ohio, Ala., Kans., N.Dak., Nebr., Okla., S.Dak., Ark., Ill., Ga., Ind., Iowa, Ariz., Idaho, Md., Alta., B.C., Greenland, Man., N.B., N.S., N.W.T., Ont., Que., Sask., Yukon, Utah, Mo., Minn., Mich., Mont., Miss., Oreg., Ky.

Discussion

Bromus tectorum is a European species that is well established in the Flora region and other parts of the world. It grows in disturbed sites, such as overgrazed rangelands, fields, sand dunes, road verges, and waste places. In the southwestern United States, Bromus tectorum is considered a good source of spring feed for cattle, at least until the awns mature. It is highly competitive and dominates rapidly after fire, especially in sagebrush areas. The resulting dense, fine fuels permanently shorten the fire-return interval, further hindering reestablishment of native species. It now dominates large areas of the sagebrush ecosystem of the western Flora region.

Specimens with glabrous spikelets have been called Bromus tectorum f. nudus (Klett & Richt.) H. St. John. They occur throughout the range of the species, and are not known to have any other distinguishing characteristics. For this reason, they are not given formal recognition in this treatment.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Bromus tectorum"
membranous +  and scarious +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Leon E. Pavlickf +
1 (?) +  and 3 (?) +
straight +
distinct +
subterminal +  and terminal +
geniculate +
1.5 cm15 mm <br />0.015 m <br /> (1 cm10 mm <br />0.01 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
0 cm0 mm <br />0 m <br /> (16 cm160 mm <br />0.16 m <br />) +
not evident +
cross +, linear +  and narrowly lanceolate +
1mm;6mm +
spikelike +
Cheatgrass +  and Downy chess +
not branching +
puberulent +
slender +
5 cm50 mm <br />0.05 m <br /> (90 cm900 mm <br />0.9 m <br />) +
not woody +
Conn. +, N.J. +, N.Y. +, Wash. +, Del. +, D.C. +, Wis. +, W.Va. +, Pacific Islands (Hawaii) +, Mass. +, Maine +, N.H. +, R.I. +, Vt. +, Fla. +, Wyo. +, N.Mex. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Calif. +, Nev. +, Va. +, Colo. +, Alaska +, Ohio +, Ala. +, Kans. +, N.Dak. +, Nebr. +, Okla. +, S.Dak. +, Ark. +, Ill. +, Ga. +, Ind. +, Iowa +, Ariz. +, Idaho +, Md. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, N.S. +, N.W.T. +, Ont. +, Que. +, Sask. +, Yukon +, Utah +, Mo. +, Minn. +, Mich. +, Mont. +, Miss. +, Oreg. +  and Ky. +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
4 +  and 8 +
terete +  and laterally compressed +
1-9(11)-veined +
always shorter +  and usually shorter +
lanceolate +
subtending +
glabrous +, pubescent +  and villous +
mucronate +  and acute +
unequal +
uncinate +
solid +  and hollow +
pubescent +  and pilose +
rounded +  and lanceolate +
0.9 cm9 mm <br />0.009 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
herbaceous +  and coriaceous +
lacerate +  and obtuse +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
0.4 cm4 mm <br />0.004 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
concealed +  and prominent +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
reduced +
5cm +  and 20cm +
3 cm30 mm <br />0.03 m <br /> (8 cm80 mm <br />0.08 m <br />) +
dry +  and fleshy +
softly retrorsely pubescent +  and pilose +
crowded +  and parallel +
compressed +
Introduced +
not viviparous +
terete +  and moderately laterally compressed +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Bromus tectorum var. nudus +, Bromus tectorum var. glabratus +  and Anisantha tectorum +
Bromus tectorum +
Bromus sect. Genea +
species +
membranous +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
aquatic +  and terrestrial +