Plants usually annual, sometimes biennial. Spikelets with parallel or converging sides in outline, terete to moderately laterally compressed, with 4-30 florets. Lower glumes 3-5-veined; upper glumes 5-9-veined; lemmas elliptic, lanceolate, obovate, or rhombic, rounded over the midvein, apices subulate, acute, acuminate, or obtuse, notched, minutely bifid, or toothed, teeth shorter than 1 mm, apices sometimes split and the teeth appearing longer; awns (0) 1 (3), straight or flexuous, recurved or divaricate.

Discussion

Bromus sect. Bromus has about 40 species that are native to Eurasia, northern Africa, and Australia; 14 species have been introduced to the Flora region.

Selected References

None.

Key

1 Lemmas inflated, 6-8 mm wide; unawned or with awns up to 1 mm long; spikelets ovate Bromus briziformis
1 Lemmas not inflated, 1-7 mm wide; awns 2-25 mm long, rarely absent; spikelet shape various. > 2
2 Lemma margins inrolled at maturity; floret bases visible at maturity; rachilla internodes visible at maturity; caryopses sometimes thick, strongly inrolled. > 3
2 Lemma margins not inrolled at maturity; floret bases concealed at maturity; rachilla internodes concealed at maturity; caryopses thin, weakly inrolled or flat. > 3
3 Anthers 2.5-5 mm long; awns straight; spikelets often purple-tinged; lower leaf sheaths with soft, appressed hairs Bromus arvensis
3 Anthers 0.7-2 mm long; awns straight or flexuous; spikelets not purple-tinged; lower leaf sheaths glabrous, loosely pubescent and glabrate, or evenly covered with stiff hairs. > 4
4 Lower leaf sheaths glabrous or loosely pubescent and glabrate; lemmas 6.5-8.5(10) mm long, margins evenly rounded; awns straight or flexuous Bromus secalinus
4 Lower leaf sheaths evenly covered with stiff hairs; lemmas 8-11.5 mm long, margins bluntly angled; awns straight Bromus commutatus
5 Lemmas 4.5-6.5 mm long, margins sharply angled; caryopses longer than the paleas Bromus lepidus
5 Lemmas 6.5-20 mm long, margins rounded or slightly to strongly angled; caryopses equaling or shorter than the paleas. > 6
6 Awns arising less than 1.5 mm below the lemma apices, erect or weakly divaricate, not twisted at the base. > 7
7 Panicle branches shorter than the spikelets; lemmas chartaceous, with prominent ribs over the veins, often concave between the veins; anthers 0.6-1.5 mm long Bromus hordeaceus
7 At least some panicle branches longer than the spikelets; lemmas coriaceous, veins obscure or distinct, not ribbed; anthers 0.7-5 mm long. > 8
8 Lower leaf sheaths with soft, appressed hairs; anthers 2.5-5 mm long; panicles 11-30 cm long Bromus arvensis
8 Lower leaf sheaths with stiff hairs; anthers 0.7-3 mm long; panicles 4-16 cm long. > 9
9 Anthers 0.7-1.7 mm long; rachilla internodes 1.5-2 mm long; lemmas 8-11.5 mm long, margins bluntly angled Bromus commutatus
9 Anthers 1.5-3 mm long; rachilla internodes 1-1.5 mm long; lemmas 6.5-8 mm long, margins rounded Bromus racemosus
6 Awns arising 1.5 mm or more below the lemma apices, erect to strongly divaricate, often twisted at the base. > 7
10 Panicle branches shorter than the spikelets, slightly curved or straight, panicles erect. > 11
11 At least the upper lemmas in each spikelet with 3 awns Bromus danthoniae
11 All lemmas 1-awned. > 12
12 Lemmas 11-20 mm long; spikelets 20-50 mm long. > 13
13 Spikelets usually single at the nodes; glumes glabrous or puberulent; panicles strongly contracted, even at maturity Bromus caroli-henrici
13 Spikelets often 2 or more at each node; glumes pilose; panicles contracted when immature, more open with age Bromus lanceolatus
12 Lemmas 6.5-11 mm long; spikelets 11-25 mm long. > 13
14 Lemmas 1.5-2 mm wide; panicles obovoid, branches sometimes verticillate Bromus scoparius
14 Lemmas 3-5 mm wide; panicles usually ovoid Bromus hordeaceus
10 At least some panicle branches as long as or longer than the spikelets, sometimes sinuous; panicles nodding. > 11
15 Lower glumes 7-10 mm long; upper glumes 8-12 mm long; panicle branches conspicuously sinuous; awns erect to weakly spreading; lemma margins rounded Bromus arenarius
15 Lower glumes 4-7 mm long; upper glumes 5-8 mm long; panicle branches sometimes sinuous; awns erect to strongly divergent; lemma margins slightly to strongly angled above the middle. > 16
16 Anthers 2.5-5 mm long; spikelets often purple-tinged; culms 80-110 cm tall Bromus arvensis
16 Anthers 1-1.5 mm long; spikelets not purple-tinged; culms 20-70 cm tall. > 17
17 Lemmas with hyaline margins 0.3-0.6 mm wide, slightly angled above the middle; branches somewhat drooping, sometimes sinuous, often with more than 1 spikelet Bromus japonicus
17 Lemmas with hyaline margins 0.6-0.9 mm wide, strongly angled above the middle; branches not drooping or sinuous, usually with 1 spikelet Bromus squarrosus

"decumbent" is not a number.

... more about "Bromus sect. Bromus"
membranous +  and scarious +
awned +  and entire +
Toothed (?) +, Bifid (?) +, Notched (?) +, Obtuse (?) +, Acuminate (?) +, Acute (?) +  and Subulate (?) +
Leon E. Pavlickf +
divaricate +
3 (?) +  and 0 (?) +
flexuous +  and straight +
distinct +
subterminal +  and terminal +
geniculate +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
not evident +
cross +, linear +  and narrowly lanceolate +
drooping;reflexed;usually ascending;spreading +
spikelike +
not branching +
ascending +  and erect +
5 cm50 mm <br />0.05 m <br /> (190 cm1,900 mm <br />1.9 m <br />) +
not woody +
Conn. +, Mass. +, N.H. +, N.J. +, N.Y. +, Calif. +, Del. +, N.C. +, Va. +, W.Va. +, Vt. +, D.C +, Wis. +, Colo. +, Kans. +, Nebr. +, Okla. +, Idaho +, Mont. +, Oreg. +, Wash. +, Wyo. +, Pacific Islands (Hawaii) +, N.Mex. +, Utah +, Maine +, R.I. +, Fla. +, Ala. +, Ark. +, Ariz. +, Ga. +, Iowa +, Ill. +, Ind. +, Ky. +, La. +, Md. +, Mich. +, Minn. +, Mo. +, Miss. +, N.Dak. +, Nev. +, Ohio +, Pa. +, S.Dak. +, Tenn. +, Tex. +, Alaska +, S.C. +, Alta. +, B.C. +, Greenland +, Man. +, N.B. +, Nfld. and Labr. +, N.S. +, N.W.T. +, Nunavut +, Ont. +, P.E.I. +, Que. +, Sask. +  and Yukon +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
4 +  and 30 +
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 +
pubescent +  and glabrous +
rounded +, rhombic +, obovate +, lanceolate +  and elliptic +
herbaceous +  and coriaceous +
lacerate +
0 cm0 mm <br />0 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
membranous +
inconspicuous +
lanceolate +
fleshy +  and membranous +
concealed +  and prominent +
2 +  and 1 +
hairy +  and glabrous +
well-developed +
reduced +
dry +  and fleshy +
converging +  and parallel +
1 +  and 60 +
not viviparous +
terete +  and moderately laterally compressed +
0.5 cm5 mm <br />0.005 m <br /> (7 cm70 mm <br />0.07 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Bromus sect. Bromus +
section +
membranous +
1 cm10 mm <br />0.01 m <br /> (?) +
biennial +  and annual +
aquatic +  and terrestrial +