Carex swanii (Fernald) Mack.
Family: Cyperaceae
Swan's Sedge
Carex swanii image
Morton Arboretum  
Culms 15-75 cm, sparsely pilose. Leaves: ligules longer than wide; blades 1.5-3 mm wide, pilose. Inflorescences: lateral spikes 5-15(-19) × 2-4 mm, proximal distant; terminal spike gynecandrous, at least 1/2 flowers pistillate, (5-)11-20 mm. Pistillate scales ovate, 1.3-2.4 × 0.6-1.4 mm, apex acute to acuminate, with awn to 0.5 mm, as long as perigynia. Staminate scales ovate, 2.4-4.1 mm, apex obtuse to acuminate. Anthers 0.7-1.3(-1.6) mm. Perigynia ascending, obscurely 5-13-veined, obovate-circular, trigonous in cross section, 1.7-2.4 × 1-1.5 mm, densely pilose; beak absent. Achenes 1.4-1.8 × 0.8-1.1 mm. 2n = 54. Fruiting late spring-early summer. Dry to wet-mesic forests, scrub; 0-1000 m; N.B., N.S., Ont., Que.; Ark., Conn., Del., D.C., Ga., Ill., Ind., Ky., Maine, Mass., Md., Mich., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.
Much like no. 160 [Carex virescens Willd.]; lvs often overtopping the stems; terminal spike 1-2 cm; pistillate spikes 1-2 cm, ellipsoid or thick-cylindric, densely fld throughout; anthers 0.7-1.5 mm; body of the pistillate scales much shorter than the perigynia, often ending in a cusp equaling the perigynium; perigynia obovoid, obscurely trigonous, 1.8-2.5 mm, blunt. Dry woods and fields; N.S. to Wis., s. to N.C. and Ark. (C. virescens var. minima)

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.
From Flora of Indiana (1940) by Charles C. Deam
Common in clearings in low woods, and in moist open oak woods; infrequent along roadsides, on flood plains, and on wooded slopes.