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Anthoxanthum
See list of 5 species in this genusSee Schouten and Veldkamp (1985) for rationale of an expanded Anthoxanthum (i.e., one that includes Hierochloe). Reference: Allred and Barkworth (2007).
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1a. Inflorescence an open to somewhat compact panicle, the lower branches ascending to wide-spreading or even drooping; glumes subequal in length; each spikelet with 1 bisexual floret and 2 unisexual florets that are staminate
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2a. Staminate florets with awned lemmas, the awns 0.6–10.5 mm long; glumes 5–8 mm long; panicle moderately compact, 1–8.5 cm tall, with (3–) 10–20 (–35) spikelets; plants subcespitose on short rhizomes up to 2 cm long
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2b. Staminate florets unawned or with short awn-tips to 0.6 (–1) mm long; glumes (2.5–) 3.5–6 mm long; panicle open (less so in subalpine plants), 4–9 (–12.5) cm tall, with 8–100 spikelets; plants with stems produced singly or a few-together on elongate rhizomes
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3a. Pubescence of lemma of bisexual floret appressed to appressed-ascending, 0.1–0.5 mm long (sometimes longer hairs can be found near the keel), tending to be concentrated toward the keel (i.e., often noticeably sparser near the margins) [Fig. 188]
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3b. Pubescence of lemma of bisexual floret loosely ascending, 0.5–1 mm long, ± uniformly distributed around the apex of the lemma [Fig. 187]
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1b. Inflorescence a densely congested panicle, the lower branches appressed to appressed-ascending (briefly somewhat open at anthesis); glumes distinctly unequal in length; each spikelet with 1 bisexual floret and 2 sterile florets
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4a. Plants perennial, with erect stems; leaves 2–6 mm wide; awn of the lower sterile lemma straight; spikelets 7–9 mm long; glumes scabrous to hirtellous
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4b. Plants annual, with geniculate, branched stems; leaves mostly narrower than 2 mm; awn of both sterile lemmas geniculate; spikelets 5–7 mm long; glumes glabrous
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Each photo represents one species in this genus.