393.
Carex
intumescens
Rudge, Trans. Linn. Soc. London, Bot. 7: 97, plate 9, fig. 3. 1804.
Carex gonflé
Plants cespitose or not, short-rhizomatous. Culms solitary or not, erect, (15—)30—80(—140) cm. Leaves 6—12; basal sheaths purplish red; sheath of distal leaf 0—1(—2.5) cm; ligules rounded, 1—8 mm; blades 8—27 cm × 3.5—8 mm. Inflorescences 2—15 cm; peduncles of proximal pistillate spikes 0.3—1.5 cm, basal 2 peduncles 0.2—2.1 cm apart; of terminal spike 0.5—4 cm; bracts leafy, sheathless, blades 6—21 × 2—6 mm. Spikes: proximal pistillate spikes 1—4, often closely aggregated and difficult to distinguish, 1—12-flowered, ovoid to obovoid, 1—2.7 × 1—2.8 cm; terminal staminate spike 1, 1—5 cm × 1—3 mm. Pistillate scales 1—3-veined, lanceolate-ovate to ovate, 4—9.5 × 2—3.8 mm, apex acute to awned, awns rough, to 6.5 mm. Anthers 3, 2—4 mm. Perigynia ascending to spreading or the basalmost reflexed, strongly 13—23-veined, lanceoloid to ovoid, 10—16.5 × 2.5—6.5 mm, with satiny luster, glabrous; beak poorly defined, 2—4.2 mm. Achenes sessile, ellipsoid to obovoid, flat to convex faces, angles not thickened, 3.5—5.7 × (2.2—)2.5—3.9 mm; style same texture as achene.
Fruiting late spring—early summer. Dry-mesic to wet coniferous, mixed, and deciduous forests, forest openings, thickets, wet meadows, ditches; 0—2000 m; Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis.
Plants from the south of the species range and from lower elevations northward are usually more robust and have more inflated, ovoid perigynia than northern or high-elevation plants. The latter are sometimes distinguished as Carex intumescens var. fernaldii L. H. Bailey.
