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Sporobolus
See list of 7 species in this genusSporobolus indicus (L.) R. Br. was reported for ME by Peterson et al. (2003), but specimens are unknown. Sporobolus nealleyi Vasey was reported for ME by Hitchcock and Chase (1950), but specimens are unknown. Reference: Peterson et al. (2003).
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1a. Plants annual, from fibrous roots; panicles terminal and axillary, 10–50 ×2–5 mm
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2a. Lemmas sparsely pubescent; spikelets 2.3–6 mm long; first glume (2.2–) 2.8–4.7 mm long; caryopsis (1.1–) 1.8–2.7 mm long
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2b. Lemmas glabrous; spikelets 1.6–3 mm long; first glume 1.5–2.4 mm long; caryopsis 1.2–1.8 mm long
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1b. Plants perennial, often with hard, knotty stem bases or rhizomes; panicles terminal or both terminal and axillary, (30–) 50–450 (–500) ×4–120 (–140) mm
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3a. Spikelets 1.5–3.2 mm long; anthers 0.3–1 mm long; apex of leaf sheath with a conspicuous tuft of hairs
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4a. Panicle dense and contracted throughout flowering and fruiting, 2–8 (–10) mm wide [Fig. 277]; branches of panicle bearing spikelets throughout their length; anthers 0.3–0.5 mm long
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4b. Panicle initially contracted, ultimately becoming open, 20–120 (–140) mm wide; branches of panicle bearing spikelets only in the apical 75–88% of the branch; anthers 0.5–1 mm long
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3b. Spikelets 3–9 (–10) mm long; anthers (1.5–) 1.7–3.2 mm long; apex of leaf sheath glabrous or pubescent, but without a conspicuous tuft of hairs
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5a. Panicle (6–) 10–110 mm wide, with appressed-ascending to spreading branches; first glume tapering to a subulate tip from the broader base; glumes equaling or exceeding the lemmas; plants lacking rhizomes
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5b. Panicle 4–16 mm wide, with appressed branches [Fig. 276]; first glume lanceolate, gradually tapering to an acuminate tip; glumes shorter than the lemmas; plants sometimes with rhizomes
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6a. Lemmas pubescent or scabrous, chartaceous, opaque; caryopsis (1.5–) 2.4–3.5 mm long, the pericarp not becoming gelatinous and slipping off the seed when wet; lower sheaths often sparsely pubescent
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6b. Lemmas glabrous and smooth, membranceous to chartaceous, hyaline; caryopsis 1–2 mm long, the pericarp gelatinizing and slipping off the seed when wet; sheaths glabrous except near apex
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Each photo represents one species in this genus.