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Key to BromusView taxon page for Bromus
(For a list of species in Bromus, use the above link.) Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots. 1. Spikelet strongly flattened; lemma  In Poaceae, the lower, generally larger of two sheathing bracts subtending a flower, generally ensheathing the palea (in a sterile lemma, the associated flower and sometimes palea are rudimentary or absent); with the palea and flower, comprising the floret. strongly keeled (sect. Ceratochloa) 2. Lemma awn  1. Bristle-like appendage or elongation, generally terminal. 2. Stiff, needle-like pappus element in Asteraceae. 0–3.5 mm; lemma veins prominent ..... B. catharticus var. catharticus 2' Lemma awn 4–15 mm; lemma veins obscure or prominent 3. Some lower inflorescence branches > 10 cm, spreading  Oriented more or less perpendicularly to the axis of attachment; often, more or less horizontal. to nodding ..... B. sitchensis var. sitchensis 3' Lower inflorescence branches < 10 cm, or if longer, erect  Upright; vertically oriented. to ascending  Curving or angling upward from base, or about 30-60 degrees less than vertical or away from axis of attachment. 4. Upper glume  In Poaceae, each of generally two sheathing bracts that are the lowermost parts of a spikelet, subtending one or more florets. ± = lowermost lemma 5. Annual; lower glume 3–5-veined, upper 9–15 mm, 5–9-veined; lemma 7–veined, margin generally hairy (occasionally glabrous), backs hairy or glabrous, awn 7–15 mm; anthers <= 0.5 mm ..... B. arizonicus 5' Perennial herb; lower glume 5–7(9)-veined, upper 11–20 mm, 7–9-veined; lemma 9–11-veined, generally hairy at least distally, awn 6–12 mm; anthers 0.6–1 mm ..... B. catharticus var. elatus (2) 4' Upper glume generally < lowermost lemma – lemma scabrous or variously hairy, marginal hairs if present similar in length to those on back 6. Inflorescence dense, pedicel  Stalk of an individual flower in an inflorescence, or the corresponding structure in fruit. generally < spikelets  1. In Poaceae, one or more florets (each a flower with subtending lemma and generally palea) and generally 2 subtending glumes; in a sterile spikelet, the flower(s) and sometimes palea(s) are rudimentary or absent. 2. In Cyperaceae, the smallest aggregation of flowers (generally more than 2) and associated bracts. ; spikelets crowded, overlapping, stalks not visible; stem 20–80 cm, occasionally bent at base; stem, leaves glabrous or occasionally scabrous; ligule  1. In Asteraceae, the 5-lobed, strap- or fan-shaped outer portion of the corolla of a ligulate flower. 2. In most Poaceae and some other grass-like plants, an appendage at the adaxial junction of leaf sheath and blade, generally membranous, sometimes formed of hairs. 3. In Isoetes and, more obscurely, in Selaginella, a membrane that wholly or partially covers a sporangium. <= 6 mm ..... B. sitchensis var. maritimus 6' Inflorescence loose to compact, at least some pedicels Stalk of an individual flower in an inflorescence, or the corresponding structure in fruit. > spikelets; spikelets not crowded or overlapping, stalk often visible; stem 30–120 cm, erect; stem, leaves often hairy; ligule generally < 4 mm 7. Most awns 1. Bristle-like appendage or elongation, generally terminal. 2. Stiff, needle-like pappus element in Asteraceae. >= (6)7 mm 1' Spikelet not strongly flattened; lemma rounded over midrib and not strongly keeled 10. Lemma tip conspicuously 2-toothed, teeth translucent, awn-like to acuminate  Having a long-tapered, sharp tip, the sides concave. , 1–7 mm; largest lemmas In Poaceae, the lower, generally larger of two sheathing bracts subtending a flower, generally ensheathing the palea (in a sterile lemma, the associated flower and sometimes palea are rudimentary or absent); with the palea and flower, comprising the floret. generally < 2 mm wide 11' Lemma awn straight, not twisted (sect. Genea) 12' Lemma mostly < 20 mm; awn 8–30 mm 13. Inflorescence dense, branches erect to ascending 14. Inflorescence branches occasionally > spikelets, shortest branch on lowest inflorescence node  Position on a stem from which one or more structures (especially leaves, buds, branches, or flowers) arise. 6–24 mm, longest branch on lowest node 0–1 × branched; sterile florets  In Poaceae, a single flower and its immediately subtending bracts (lemma and generally palea, the lemma subtending the palea when the latter is present); in a sterile floret, the flower and sometimes palea are rudimentary or absent. <= 3; inflorescence internodes  Segment of an axis (generally a stem) between successive positions (nodes) from which one or more structures (especially leaves, buds, branches, or flowers) arise. gradually reduced upwards; florets not overlapping at maturity ..... B. madritensis 14' Inflorescence branches < spikelets, shortest branch on lowest inflorescence node <= 6 mm, longest branch on lowest node 2–5 × branched; sterile florets 3+; inflorescence internodes abruptly reduced upwards; florets overlapping at maturity ..... B. rubens 13' Inflorescence open, branches spreading to nodding 15. Spikelets 1(3) per inflorescence branch; inflorescence generally simple  Composed of a single part; undivided; unbranched. ; branches > spikelets (< when inflorescence reduced to 1(3) spikelets); lemma 13–20 mm; awn 15–30 mm ..... B. sterilis 15' Spikelets 1–14 per inflorescence branch; inflorescence branched 1–5 ×; branches < or > spikelets; lemma 9–13 mm; awn 8–18 mm ..... B. tectorum 10' Lemma tip entire  Having margins that are continuous and smooth (i.e., without teeth, lobes, etc.). or inconspicuously 2-toothed, teeth generally not translucent, 0–3 mm; largest lemmas generally > 2 mm wide (except in Bromus vulgaris) 16. Annual; lower glume 3(5)-veined; upper glume 5–9-veined (sect. Bromus) 17. Lemma inflated, 6–8 mm wide; awn 0–1 mm; spikelets ovate  Egg-shaped (i.e., widest below the middle) in two dimensions (i.e., in one plane), as a leaf. ..... B. briziformis 17' Lemma not inflated, 1–5 mm wide; awn 2–20 mm; spikelets lanceolate  Narrowly elongate, widest in the basal half, often tapered to an acute tip. to lance-ovate 18. Lemma papery, veins generally strongly raised; inflorescence generally ± dense 19' Awn from < 1.5 mm below lemma tip, straight (curved); generally some pedicels > spikelets; inflorescence branches erect to spreading ..... B. hordeaceus 18' Lemma leathery, veins generally not strongly raised; inflorescence generally ± open 20. Awn from 1.5–5 mm below lemma tip 21. Lower glume 7–10 mm; upper glume 8–12 mm; inflorescence branches conspicuously S-curved ..... B. arenarius 21' Lower glume 4–7 mm; upper glume 5–9.5 mm; inflorescence branches ± wavy, sometimes S-curved 22. Inflorescence panicle-like, branches generally with > 1 spikelet 1. In Poaceae, one or more florets (each a flower with subtending lemma and generally palea) and generally 2 subtending glumes; in a sterile spikelet, the flower(s) and sometimes palea(s) are rudimentary or absent. 2. In Cyperaceae, the smallest aggregation of flowers (generally more than 2) and associated bracts. ; membranous lemma margin 0.3–0.6 mm wide ..... B. japonicus 22' Inflorescence generally raceme-like, branches generally with 1 spikelet; membranous lemma margin 0.6–0.9 mm wide ..... B. squarrosus 20' Awn from < 1.5 mm below lemma tip 23. Anthers 2.5–5 mm; spikelets lance-linear, narrowing only slightly towards tip; lower leaf  Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets). sheaths with dense, softly appressed  Parallel or nearly parallel to and often in contact with surface of origin; used to describe the disposition of hairs, leaves, pedicels, etc. hairs; spikelets generally purple-tinged ..... [B. arvensis] 23' Anthers < 2.5(3) mm; spikelets lance-ovate, narrowing conspicuously towards tip; lower leaf sheaths glabrous or sparsely to densely stiff-hairy; spikelets not purple-tinged. 24. Lower leaf sheath  A surrounding or partially surrounding, often tubular structure or part of a structure, such as a leaf base in Apiaceae or Poaceae. glabrous or sparsely short-hairy; spikelet widening in fruit, stalk becoming tough, persistent, visible as lemma wraps around fruit; fruit U- and V-shaped in ×-section ..... B. secalinus 24' Lower leaf sheath long-hairy; spikelets not widening substantially in fruit, lemmas generally continuing to obscure stalks; fruit flat or C-shaped in ×-section 25. Inflorescence broad, spreading, some inflorescence branches > 4 cm, 1–3 spikelets per branch; lowest lemma awn generally < other awns; spikelets 15–30 mm; 2nd lowest lemma 7.5–11 mm, glabrous or hairy, margin often broadly angled; anthers 1.3–2.5 mm ..... B. commutatus 25' Inflorescence narrow, generally unbranched, inflorescence branches < 4 cm, 1 spikelet per branch; all awns ± equal; spikelet 11–18 mm; 2nd lowest lemma 7–9 mm, glabrous, margin often smoothly curved; anthers 1.5–3 mm ..... B. racemosus 16' Perennial herb, bases fibrous  1. Pertaining to structures that are composed at least in part of more or less thread-like but usually tough elements (e.g., Yucca leaves). 2. Pertaining to a root system composed of many roots similar in length and thickness (e.g., grass roots). , rhizomes generally 0; lower glume 1(3)-veined; upper glume 3(5)-veined (sect. Bromopsis) 26' Rhizomes 0; awn 1.5–11 mm 27. Lower glume generally 3-veined 29. Ligule (1.5)2–4 mm; glume glabrous; upper glume 7–11 mm; leaf blade  Expanded portion of a leaf, petal, or other structure, generally flat but sometimes rolled, cylindric, wavy, or cupped. , sheath glabrous ..... B. laevipes 30' Lemma awn 3–9 mm; blade 3–12 mm wide; anthers 3–7 mm 31. Leaf blade, basal  At or near the base of a plant or plant part. Especially said of leaves clustered near the ground or of a placenta confined to the base of an ovary. sheath hairy; stem nodes Position on a stem from which one or more structures (especially leaves, buds, branches, or flowers) arise. 3–7; inflorescence branches generally spreading > 90° ..... B. grandis (2) 31' Leaf blade, basal sheath glabrous; stem nodes 2–3(4); inflorescence branches generally ascending to spreading <= 90° ..... B. orcuttianus (3) 27' Lower glume generally 1-veined 32. Glumes glabrous or minutely scabrous 33' Inflorescence broader in flower, > 2 cm wide; branches erect, ascending, or nodding, generally ± widely spreading 34' Ligule 0.5–3 mm; lemma awn (2)3–7(9) mm 35. Lemma margin not densely hairy; lemma awn (4)5–7(9) mm; inflorescence branches generally ascending to spreading <= 90° ..... B. orcuttianus (3) 35' Lemma margin densely hairy; lemma awn (2)3–5(6.5) mm; inflorescence branches spreading to nodding > 90° 36. Lemma back glabrous or sparsely hairy with hairs to 0.1 mm; anthers(0.9)1–1.4(1.6) mm; upper glumes (6.2)7.1–8.5(9.5) mm; basal sheath glabrous or long-hairy; upper stem blade hairy on upper surface; upper stem sheath, nodes generally hairy; fruit (5.4)6.2–7.2(7.5) mm ..... B. ciliatus 36' Lemma back sparsely to densely hairy with hairs > 0.1 mm; anthers (1.2)1.6–2.7(3.4) mm; upper glumes (7.8)8.9–11.3(13.2) mm; basal sheath densely, ± short-hairy, upper stem sheath glabrous; upper stem blade upper surface glabrous; upper stem nodes generally glabrous; fruit (6.9)7.7–9.7(10.5) mm ..... B. richardsonii 37. Inflorescence narrow at flower, <= 2 cm wide, branches erect or tightly ascending; leaf blade, sheath glabrous ..... B. suksdorfii (2) 37' Inflorescence broader at flower, > 2 cm wide, branches erect, ascending, or nodding; leaf blade, sheath hairy or glabrous 38. Ligule (2)3–6(7) mm; lemma awn (4)6–11 mm; inflorescence branches glabrous or scabrous ..... B. vulgaris (2) 38' Ligule 1–3 mm; lemma awn 3–7(9) mm; inflorescence branches hairy 39' Lower sheath densely short-stiff-hairy, hairs <=1 mm; leaf blade hairy
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