Bromus hordeaceus |
Bromus tectorum |
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brome mou, lesser soft brome, lopgrass, soft brome, soft chess |
cheat brome, cheat grass, downy brome, downy chess, drooping brome |
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Habit | Plants annual or biennial. | Plants annual. | ||||||||||||
Culms | 2-70 cm, erect or ascending. |
5-90 cm, erect, slender, puberulent below the panicle. |
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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. |
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Panicles | 1-13 cm long, 1-4 cm wide, erect, usually ovoid, open, becoming dense, occasionally reduced to 1 or 2 spikelets; branches shorter than the spikelets, ascending to erect, straight or almost so. |
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. |
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Spikelets | (11)14-20(23) mm, lanceolate, terete to moderately laterally compressed; florets 5-10, bases concealed at maturity; rachilla internodes concealed at maturity. |
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. |
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Glumes | pilose or glabrous; lower glumes 5-7 mm, 3-5-veined; upper glumes 6.5-8 mm, 5-7-veined; lemmas 6.5-11 mm long, 3-5 mm wide, lanceolate, chartaceous, antrorsely pilose to pubescent, or glabrous proximally or throughout, 7-9-veined, lateral veins prominently ribbed, rounded over the midvein, hyaline margins abruptly or bluntly angled, not inrolled at maturity, apices acute, bifid, teeth shorter than 1 mm; awns 6-8 mm, usually arising less than 1.5 mm below the lemma apices, straight to recurved at maturity; anthers 0.6-1.5 mm. |
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. |
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Caryopses | equaling or shorter than the paleas, thin, weakly inrolled to flat. |
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Lower | sheaths densely, often retrorsely, pilose; upper sheaths pubescent or glabrous; ligules 1-1.5 mm, hairy, obtuse, erose; blades 2-19 cm long, 1-4 mm wide, abaxial surfaces glabrous or hairy, adaxial surfaces hairy. |
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2n | = 28. |
= 14. |
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Bromus hordeaceus |
Bromus tectorum |
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Distribution |
AK; AR; AZ; CA; CO; CT; DE; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; WA; WI; WY; HI; AB; BC; LB; NB; NS; NT; ON; QC; YT; Greenland
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AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; HI; AB; BC; MB; NB; NS; NT; ON; QC; SK; YT; Greenland
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Discussion | Bromus hordeaceus is native to southern Europe and northern Africa. It is weedy, growing in disturbed areas such as roadsides, fields, sandy beaches, and waste places, and can be found in many locations in the Flora region, with the exception of the central Canadian provinces and most of the southeastern United States. Its origin is obscure. Ainouche et al. (1999) reviewed various suggestions, and concluded that at least one of its diploid ancestors may have been an extinct or undiscovered species related to B. caroli-henrici, a diploid species. The four subspecies are usually morphologically distinct. Ainouche et al. (1999), however, found no evidence of genetic differentiation among them. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 24, p. 232. | FNA vol. 24, p. 226. | ||||||||||||
Parent taxa | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Bromus | Poaceae > subfam. Pooideae > tribe Bromeae > Bromus > sect. Genea | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | B. mollis | B. tectorum var. nudus, B. tectorum var. glabratus, Anisantha tectorum | ||||||||||||
Name authority | L. | L. | ||||||||||||
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