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Carex Group 5
See list of 32 species in this group-
1a. Leaf sheaths and blades glabrous or scabrous, but not pubescent
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2a. Perigynia (5.3–) 6–11.5 mm long, the beak terminated by 2 stiff teeth (1–) 1.2–2.3 (–2.8) mm long (in part)
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2b. Perigynia 2.2–6.5 mm long, the beak without teeth or with teeth 0.1–0.8 mm long
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3a. Lowermost bract of inflorescence (excluding basal spikes) bladeless or with a blade up to 2 mm long, strongly anthocyanic
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3b. Lowermost bract of inflorescence with blades more than 3 mm long (usually much longer), not or scarcely anthocyanic
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4a. Leaf sheaths with cross-septa connecting the longitudinal veins (sometimes the cross-veins are few and obscure); adaxial surface of leaf blades usually with 2 marginal veins that are more prominent than midvein
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5a. Leaf blades adaxially scabrous; beak of perigynium slightly bent, obscurely bidentate at tip
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5b. Leaf blades adaxially smooth or scabrous only along margins and/or near tip; beak of perigynium straight, terminated by two, stiff teeth 0.4–0.8 mm long (with a soft, obscurely toothed tip in C. vestita) (in part)
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4b. Leaf sheaths without cross-septa connecting the longitudinal veins or these few and obscure; adaxial surface of leaf blades without 2 marginal veins more prominent than midvein
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6a. Vegetative leaf blades involute to triangular-channeled, tapering to an elongate, filiform, curling tip; plants of hydric communities, including peatlands, lakeside fens, and graminoid marshes (in part)
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6b. Vegetative leaf blades ± flat to V-shaped in cross-section, pointed at the apex, but not long-prolonged into very thin, curling tips; plants primarily of mesic to xeric soils (frequently of wetlands in C. flacca, but that species with arching or drooping lower spikes)
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7a. Basal spike of leafy, flowering stems long-peduncled, often arching or even drooping; lateral spikes cylindric, 20–45 mm long, the basalmost with more than 30 perigynia
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7b. Basal spike of leafy, flowering stems sessile or short-peduncled, erect to ascending; lateral spikes subglobose to short-obloid or short-ellipsoid, 2–15 mm long, the basalmost with (1–) 3–22 perigynia
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8a. Style base expanded into a circular ring and persistent at summit of achene; beak of perigynium ca. 0.2 mm long; carpellate scales with a scabrous awn up to 2 mm long
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8b. Style base not expanded, deciduous; beak of perigynium 0.4–2 mm long; carpellate scales awnless or with an awn shorter than 1 mm (in part)
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1b. Leaf sheaths and often the blades pubescent
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9a. Perigynia 4.8–12 mm long, with a beak terminated by 2 stiff teeth 0.8–3 mm long; style persistent at summit of achene (in part)
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9b. Perigynia 1.7–5 mm long, beakless or beaked and then terminated by teeth up to 0.7 mm long; style deciduous
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10a. Perigynia 1.7–4 mm long, beakless or essentially so; uppermost spike bearing some perigynia (in part)
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10b. Perigynia 3.5–5 mm long, with a prominent, bidentate beak; uppermost spike entirely staminate
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Each photo represents one species in this subgroup.