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. > 5
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. > 10
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. > 14
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. > 15
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
... more about "Bromus sect. Bromus"
Leon E. Pavlickf +
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Gramineae +
Bromus sect. Bromus +
section +