| 1 |
Spikelets with 2 or more fertile florets |
|
(2) |
| + |
Spikelets with 1 fertile floret |
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(8) |
| |
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| 2 (1) |
Ovary hairy; spikelets large, 7–45 mm |
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(3) |
| + |
Ovary glabrous or almost so; spikelets small, 2.5–10 mm |
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(4) |
| |
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| 3 (2) |
Perennial; glumes unequal, 1–7-veined. |
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75 Helictotrichon |
| + |
Annual; glumes subequal, 7–11-veined. |
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77 Avena |
| |
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| 4 (2) |
Lemmas keeled |
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(5) |
| + |
Lemmas rounded on back |
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(6) |
| |
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| 5 (4) |
Lemmas awned from back. |
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78 Trisetum |
| + |
Lemmas awnless or with a subapical awn-point. |
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79 Koeleria |
| |
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| 6 (4) |
Annual; florets arising at about same level; rachilla extension absent. |
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82 Aira |
| + |
Perennial; florets separated by an internode; rachilla extension present |
|
(7) |
| |
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| 7 (6) |
Panicle glistening; lemma apex erose. |
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80 Deschampsia |
| + |
Panicle not glistening; lemma apex 4-toothed. |
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87 Deyeuxia |
| |
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|
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| 8 (1) |
Inflorescence of several racemes along a central axis. |
|
92 Beckmannia |
| + |
Inflorescence a panicle, sometimes spikelike |
|
(9) |
| |
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|
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| 9 (8) |
Fertile floret accompanied by staminate or sterile florets |
|
(10) |
| + |
Fertile floret solitary, with or without a rachilla extension |
|
(13) |
| |
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|
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| 10 (9) |
Spikelets with 2 florets |
|
(11) |
| + |
Spikelets with 3 florets, the 2 lower staminate or barren (reduced to small scales in Phalaris) |
|
(12) |
| |
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| 11 (10) |
Spikelet disarticulating above glumes; lower floret staminate. |
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76 Arrhenatherum |
| + |
Spikelet disarticulating below glumes; upper floret staminate. |
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81 Holcus |
| |
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| 12 (10) |
Lower lemmas rudimentary; plants without coumarin. |
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83 Phalaris |
| + |
Lower lemmas well developed; plants scented with coumarin. |
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84 Anthoxanthum |
| |
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|
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| 13 (9) |
Spikelets in compact umbellate clusters; glumes absent. |
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85 Coleanthus |
| + |
Spikelets in an open, contracted or spikelike panicle; glumes present |
|
(14) |
| |
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| 14 (13) |
Spikelets falling entire |
|
(15) |
| + |
Spikelets disarticulating above glumes |
|
(19) |
| |
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| 15 (14) |
Spikelets shed with a basal stipe. |
|
89 Polypogon |
| + |
Spikelets shed without a basal stipe |
|
(16) |
| |
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| 16 (15) |
Panicle open |
|
(17) |
| + |
Panicle spikelike or capitate; stamens usually 3 |
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(18) |
| |
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| 17 (16) |
Glumes indistinctly 3-veined; lemma with awnlet; stamen 1. |
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90 Cinna |
| + |
Glumes prominently 3-veined; lemma awnless; stamens 3. |
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91 Cyathopus |
| |
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| 18 (16) |
Lemma awned from back. |
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93 Alopecurus |
| + |
Lemma awnless. |
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94 Phleum |
| |
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|
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| 19 (14) |
Glumes slightly shorter than floret. |
|
87 Deyeuxia |
| + |
Glumes equaling or longer than floret |
|
(20) |
| |
|
|
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| 20 (19) |
Glumes mucronate. |
|
86a ×Agropogon |
| + |
Glumes acute to acuminate |
|
(21) |
| |
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| 21 (20) |
Spikelets usually less than 5 mm; callus glabrous or shortly hairy; lemma hyaline. |
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86 Agrostis |
| + |
Spikelets often more than 5 mm; callus bearded, hairs 1/3 as long as to longer than floret (if shorter, penicillate rachilla extension present); lemma membranous to firm |
|
(22) |
| |
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| 22 (21) |
Lemma at least 3/4 as long as glumes, usually firm; callus hairs almost as long as to clearly shorter than floret; rachilla extension present, penicillate |
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87 Deyeuxia |
| + |
Lemma 1/2–2/3 as long as glumes, membranous; callus hairs often much exceeding floret; rachilla extension absent, or if present glabrous or shortly hairy. |
|
88 Calamagrostis |
