Plants cespitose or colonial, short- to long-rhizomatous. Culms reddish purple, reddish brown, or brown at base. Leaves: basal sheaths fibrous or not; sheath fronts membranous; sheaths and blades distinctly, sparsely septate-nodulose, blades V- or W-shaped, flat, or, rarely, round in cross section when young; widest leaves 0.9–16 mm, mostly more than 4 mm, smooth or papillose. Inflorescences racemose, with 2–10 spikes; proximal bracts leaflike, sheathless or short-sheathed, less than 4 mm, shorter or longer than diameter of stem; lateral spikes pistillate, pedunculate, prophyllate; terminal spike staminate. Proximal pistillate scales green to dark brown, margins entire, apex retuse or obtuse to acuminate, awnless or awned, awn scabrous or smooth; distal scale with awn at least 1/2 as long as body. Perigynia ascending to spreading or reflexed, 0–25-veined, at least slightly inflated, sometimes stipitate, narrowly elliptic to ovate, rounded-trigonous to terete in cross section, 2–12 mm, base rounded or truncate, apex tapering or abruptly contracted to beak, somewhat glossy, not papillose, glabrous; beak 0.2–6 mm, emarginate to bidentate, teeth rarely reflexed, 0.1–2.1 mm. Stigmas (2–)3. Achenes trigonous or, rarely, biconvex, almost as large as bodies of perigynia; style persistent.

Distribution

Temperate to arctic regions of the Northern Hemisphere and scattered in cooler regions of the tropics and Southern Hemisphere.

Discussion

Species ca. 45 (19 in the flora).

Carex sect. Vesicariae, as defined here, includes species placed by K. K. Mackenzie (1931–1935, parts 2–3, pp. 429–434) in sections Vesicariae and Pseudocypereae (Tuckerman) H. Christ. The two sections are distinguished on the basis of the number of veins on the perigynium surface and the presence or absence of scabrous awns on the pistillate scales. Some species share characteristics of both the Vesicariae and the Pseudocypereae, suggesting that these sections are best combined.

Selected References

None.

Lower Taxa

Carex baileyi, Carex bullata, Carex comosa, Carex elliottii, Carex exsiccata, Carex hystericina, Carex lurida, Carex membranacea, Carex oligosperma, Carex pseudocyperus, Carex retrorsa, Carex rostrata, Carex rotundata, Carex saxatilis, Carex schweinitzii, Carex thurberi, Carex tuckermanii, Carex utriculata, Carex vesicaria

Key

1	Pistillate scales scabrous-awned, margins often ciliate.	> 2
1	Pistillate scales awnless (rarely the proximal awned in C. rostrata and C. utriculata), margins entire.	> 8
2	Plants extensively colonial, not cespitose, rhizomes elongate; apex of staminate scales acute to acuminate, essentially smooth-margined except at tip; perigynia 7–11-veined.	Carex schweinitzii
2	Plants densely to loosely cespitose, rhizomes connecting individual culms in clump no more than 10 cm; apex of at least some staminate scales scabrous-awned, sometimes also ciliate-margined; perigynia 5–12- or 12–25-veined.	> 3
3	Perigynia 5–12-veined, veins separate nearly to beak apex, bodies broadly elliptic to ± round, (1.8–)2–4.2 mm wide; achenes rough-papillose.	> 4
3	Perigynia 12–25-veined, veins (except for 2 prominent laterals) confluent at or proximal to mid beak, bodies elliptic to lance-ovate, 1–2.2 mm wide; achenes smooth.	> 5
4	Spikes (12–)15–22 mm thick; widest leaves (4–)4.5–13 mm wide; if spikes less than 15 mm thick, then usually less than 2.5 times as long as wide; perigynia (6–)6.5–10.8 mm; beak 0.7–0.9 times length of body.	Carex lurida
4	Spikes 9–14(–15) mm thick; widest leaves 2.4–4(–5) mm wide; spikes usually 2.5–3.5 times as long as wide; perigynia 4.8–6.6(–7.6) mm; beak 0.7–1.3 times length of body.	Carex baileyi
5	Perigynia ± reflexed when mature, leathery, uninflated, compressed-triangular, strongly and closely veined with most veins separated by less than 2 times their width; longest beak teeth 0.7–2.1(–2.8) mm.	> 6
5	Perigynia spreading to ascending, herbaceous, ± inflated, terete to somewhat flattened, many veins separated by more than 3 times their width; longest beak teeth 0.3–0.9 mm.	> 7
6	Spikes 12–18 mm thick; beak teeth strongly out-curved, longest 1.3–2.1 (–2.8) mm.	Carex comosa
6	Spikes 9–12 mm thick; beak teeth straight or slightly out-curved, longest teeth 0.7–1.2(–1.4) mm.	Carex pseudocyperus
7	Perigynium beak 1.9–2.8 mm; pistillate scale bodies mostly truncate to retuse at apex, awn mostly longer than body.	Carex hystericina
7	Perigynium beak 0.9–1.8 mm; at least middle and distal pistillate scale bodies obtuse to acuminate, tapering to awn shorter than body.	Carex thurberi
8	Leaves filiform-involute, wiry, (0.5–)1–3(–3.2) mm wide; culms round or obtusely trigonous.	> 9
8	Leaves flat, U-, V-, or W-shaped in cross section, widest 1.5–12(–15) mm wide; culms round to trigonous.	> 10
9	Perigynia distinctly veined, veins extending into beak, 4–6.7 × 2.5–3.4 mm, leathery.	Carex oligosperma
9	Perigynia obscurely veined, veins not extending into beak, 2.5–3.9(–4.2) × 1.4–2.3 mm, membranaceous.	Carex rotundata
10	Perigynia obscurely veined, veins not running into beak, often dark-colored; beak less than 1 mm, emarginate at apex; stigmas 2 or 3.	> 11
10	Perigynia distinctly veined, veins running into beak, often green or straw colored; beak usually more than 1 mm, distinctly toothed at apex; stigmas 3.	> 12
11	Stigmas 2; perigynia ascending; culms arising from short, congested rhizomes.	Carex saxatilis
11	Stigmas 3; perigynia spreading or reflexed; culms arising from long, lax rhizomes.	Carex membranacea
12	Achenes asymmetric, deeply indented or invaginated on 1 face; widest perigynia (4–)4.5–7 mm wide; beak 2.4–4.8 mm.	Carex tuckermanii
12	Achenes symmetric, not indented or invaginated; widest perigynia (1.5–)2.5–3.5(–4.5) mm wide; beak 1–4.2(–4.8) mm.	> 13
13	Perigynium beak 2.4–4.2(–4.8) mm, finely scabrous, at least near the tip and on teeth; widest leaves 1.8–4.3(–5) mm wide.	Carex bullata
13	Perigynium beak 1–4.5 mm, smooth; widest leaves 1.5–15 mm wide.	> 14
14	Pistillate spikes globose or short-ovoid, ca. 3–20-flowered.	Carex elliottii
14	Pistillate spikes cylindric, ca. 20–150-flowered.	> 15
15	Bract of proximal pistillate spike (isolated spikes from long-sheathing bracts on proximal part of stem excepted) (2.5–)3–9 times longer than inflorescence; staminate spike often 1, slightly if at all elevated beyond summit of crowded pistillate spikes; perigynia reflexed.	Carex retrorsa
15	Bract of proximal pistillate spike shorter to no more than 2.5 times longer than inflorescence; staminate spikes 2–4(–5), well elevated beyond summit of separate pistillate spikes; perigynia spreading or ascending.	> 16
16	Leaves strongly papillose on adaxial surface, U-shaped in cross section, whitish green, widest leaves 1.5–4.5(–7.5) mm wide; culms terete to trigonous, smooth distally; plants rhizomatous; ligules as long as wide.	Carex rostrata
16	Leaves smooth or scabrous on adaxial surface, flat or folded, pale to dark green, widest leaves (2.5–)3–12(–15) mm wide; culms trigonous, scabrous distally; plants rhizomatous or not; ligules shorter to longer than wide.	> 17
17	Plants colonial; rhizomes elongate, creeping; widest leaves 4.5–12(–15) mm wide; ligules as long as wide; basal sheaths usually spongy-thickened, slightly red tinged or not.	Carex utriculata
17	Plants cespitose; rhizomes short; widest leaves 1.8–6.5 mm wide; ligules longer than wide; basal sheaths not spongy, thickened and often tinged with reddish purple.	> 18
18	Perigynia ovate to narrowly ovate, longest 4.8–7.5(–8.2) mm, 2–3.5 times as long as wide, papery, inflated, apex contracted; beak distinct.	Carex vesicaria
18	Perigynia lanceolate, longest 7.5–10.1 mm, 3.4–5 times as long as wide, leathery, not or slightly inflated, apex gradually tapering; beak indistinct.	Carex exsiccata