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Poaceae Group 3
See list of 15 genera in this group-
1a. Spikelets, excluding the awns, 19–26 mm long; glumes 5- to 11-veined
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1b. Spikelets, excluding the awns, up to 18 mm long; glumes 1- to 5-veined
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2a. Rachilla long-pubescent, the longer hairs (2–) 3–7 mm long; ligule of upper stem leaves 5–8 mm long
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2b. Rachilla glabrous or pubescent with hairs up to 2 mm long; ligule of upper stem leaves as long as 5 (–6) mm (3–12 mm long in Deschampsia cespitosa and 1–8 mm long in Ventenata)
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3a. Spikelets with 2 florets [Fig. 234]
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4a. Spikelets 9–15 mm long; upper lemma with an awn 10–16 mm long, terminated by 2 setaceous teeth 1–2 mm long; upper glume 3- to 9-veined (in part)
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4b. Spikelets 1.7–11 mm long; upper lemma without an awn or with an awn (0.5–) 1–9 mm long, entire or bifid at the apex; upper glume 1- to 3-veined
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5a. Lower lemma of spikelet (or both lemmas) lacking an awn
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6a. Neither lemma of spikelet with an awn; reproductive stems glabrous or minutely scabrous (in part)
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6b. Upper lemma of spikelet with a bent or hooked awn [Fig. 234]; reproductive stems pilose on at least the nodes (glabrous or sparsely pubescent in Holcus mollis)
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5b. Lower lemma of spikelet (and usually both lemmas) with an awn
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7a. Florets of a given spikelet dimorphic—the lower unisexual, the upper bisexual; lemma awns dimorphic—that of the lower lemma 10–20 mm long and bent near the middle, that of the upper to 6 mm long and straight
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7b. Florets of a given spikelet monomorphic, both bisexual; lemma awns relatively monomorphic, similar in shape, the upper slightly shorter if at all
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8a. Lemma awns composed of 2 distinctly unlike members—the basal portion brown and spiraled, the apical portion white and distally thickened—the two members separated by a ciliate joint
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8b. Lemma awns tapering to the apex, not consisting of 2 articulate members separated by a ring of cilia
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9a. Awn (when present) attached above the middle of the lemma [Fig. 281]; lemma apex bifid
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10a. Lemmas with awns 3–9 mm long, the awns conspicuously surpassing the apex of the lemma [Fig. 281]; callus of lemma pubescent with hairs up to 1 mm long (in part)
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10b. Lemmas unawned or rarely with rudimentary awns shorter than 2 mm, the awns, when present, not or scarcely surpassing the apex of the lemma; callus of lemma pubescent with hairs 1.5–2 mm long (in part)
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9b. Awn attached below the middle of the lemma [Fig. 208]; lemma apex entire to bifid
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11a. Apex of lemma terminated by 2 setaceous teeth (caution: the terminal teeth are sometimes intertwined and difficult to observe); glumes 2.3–3.3 mm long; rachilla not prolonged beyond upper floret
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11b. Apex of lemma entire or erose, but without terminal teeth; longer glumes 2.7–6.1 mm long; rachilla prolonged beyond upper floret
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12a. Glumes slightly shorter than to slightly exceeding the lemmas [Fig. 208]; anthers 1.3–3 mm long; stems with prominent tufts of basal leaves (in part)
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12b. Glumes much exceeding lemmas, approximately twice as long [Fig. 282]; anthers 0.4–0.8 mm long; stems without prominent tufts of basal leaves
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3b. Spikelets with 3 or more florets [Fig. 281]
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13a. Lemma apex dissected into numerous, spreading awns
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13b. Lemma without awns or with a single awn
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14a. Upper glume 3- to 9-nerved; upper lemma with an awn 10–16 mm long arising from the abaxial keel, terminated by 2 setaceous teeth 1–2 mm long (in part)
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14b. Upper glume 1- to 3-veined (up to 5 (–7)-veined in Danthonia, but that genus usually with more than 3 florets per spikelet); upper lemma without an awn or with an awn to 10.5 mm long, with or without apical teeth, the awn (when present) emerging from between the apical teeth or from the abaxial keel
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15a. Spikelets with 3–12 florets; lemmas with an awn arising from between 2 terminal teeth; spikelets 7–16 mm long
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15b. Spikelets with 3 or 4 florets; lemmas with or without awns, the awns, when present, not arising from between apical teeth; spikelets 3.2–9 mm long
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16a. Upper floret bisexual, of different form from the 2 lower, unisexual and staminate florets; 2 lower lemmas evidently pubescent over the surfaces, at least near the apex (note: the hairs visible at low magnification)
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16b. Florets all bisexual, progressively reduced in size upward; lemmas minutely and/or rather sparsely scabrous-hirtellous over their surfaces (note: the callus and rachilla segments may be evidently pubescent; lemmas pilose in some forms of Trisetum spicatum)
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17a. Panicle branches densely pubescent; apex of lemma entire; rachilla segments glabrous or pubescent with hairs shorter than 1 mm
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17b. Panicle branches antrorsely scabrous; apex of lemma bifid; rachilla segments pubescent with hairs 0.4–2 mm long, these usually longer than 1 mm in the distal portion of the segment
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18a. Lemmas with awns 3–9 mm long, the awns conspicuously surpassing the apex of the lemma [Fig. 281]; callus of lemma pubescent with hairs up to 1 mm long (in part)
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18b. Lemmas unawned or with awns shorter than 2 mm, the awns, when present, not or scarcely surpassing the apex of the lemma; callus of lemma pubescent with hairs 1.5–2 mm long (in part)
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Each photo represents one genus in this subgroup.