Plants cespitose or not, rarely colonial, short to long rhizomatous. Culms purplish or reddish, rarely brown at base. Leaves: basal sheaths not fibrous; sheath fronts membranous; sheaths and larger leaves distinctly septate-nodulose; blades V-shaped in cross section when young, glabrous. Inflorescences racemose, with 2–6(–9) spikes; proximal bracts leaflike, sheathless or sheath less than 4 mm, shorter or longer than diam. of stem; lateral spikes pistillate or the distal 1(–5) staminate or androgynous, globose, ovoid, or cylindric, pedunculate, prophyllate; terminal spike staminate. Proximal pistillate scales with apex obtuse to acuminate, often awned. Perigynia ascending to spreading, distinctly 15–20-veined, sometimes stipitate, inflated, ovate, ± round in cross section, 10–20 mm, base cuneate to rounded, apex tapering or abruptly beaked, glabrous or sparsely hairy; beak conspicuously bidentate, teeth not more than 1 mm. Stigmas 3. Achenes trigonous, smaller than bodies of perigynia; style persistent.

Distribution

e North America.

Discussion

Species 6 (6 in the flora).

Members of Carex sect. Lupulinae have the largest perygynia of all Carex. Mature achenes are critical for identification of some species.

Selected References

None.

Lower Taxa

Carex gigantea, Carex grayi, Carex intumescens, Carex louisianica, Carex lupuliformis, Carex lupulina

Key

1	Sheath of the distal nonbracteal leaf 0–1.5(–2.5) cm; beak of perigynium 1.5–4.2 mm; achenes elliptic or obovate; spikes globose to short-ovoid.	> 2
1	Sheath of the distal nonbracteal leaf usually 1.7 cm or longer; beak of perigynium 4.5–10 mm; achenes rhombic or nearly triangular; spikes ovoid to cylindric.	> 3
2	Perigynia radiating out in all directions to form globular spike, rhombic-ovoid, base cuneate, 8–35 per spike.	Carex grayi
2	Perigynia ascending to spreading or, sometimes, the basalmost reflexed to form an ovoid to obovoid spike, lanceoloid to ovoid, base convex, 1–12(–20) per spike.	Carex intumescens
3	Achenes distinctly wider than long, widest beyond midle; perigynia stiffly spreading at right angles to rachis.	Carex gigantea
3	Achenes as wide as long as or longer, widest near middle; perigynia ascending.	> 4
4	Angles of achenes pointed, often knobbed, with hard, nipplelike points; achenes (2.2–)2.4–3.4 mm wide, often nearly as wide as long.	Carex lupuliformis
4	Angles of achenes smoothly curved, not pointed or knobbed; achenes 1.7–2.6(–2.8) mm wide, longer than wide.	> 5
5	Staminate peduncle 0.5–6(–7) cm, shorter than to exceeding distal pistillate spike by no more than 2 cm; plants loosely cespitose or not, short-rhizomatous.	Carex lupulina
5	Staminate peduncle (3–)6–18 cm, usually exceeding distal pistillate spike by 2–12 cm; plants loosely colonial, long-rhizomatous.	Carex louisianica