Carex diandra Schrank
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stems densely clustered, 3–10 dm, aphyllopodic, rather slender above; lvs ± elongate, ± flat, mostly 1–2.5 mm wide; sheaths ventrally pale and red-dotted, prolonged 2–3 mm beyond the base of the blade; spikes androgynous, ± numerous, small, sessile, aggregated into a compact but branched infl 2–3.5(–5) cm long and seldom over 1 cm thick; bracts small, setaceous or almost like the pistillate scales; stamens 3 (in spite of the name); scales largely hyaline-scarious and stramineous or brownish, with firmer, sometimes shortly excurrent midrib; perigynia ovate or lance-ovate, 2.4–3 mm, half as wide, usually dark brown, shining, ± spreading, very firm and thick-walled, the nerveless ventral surface slightly convex and often exposed in the spike, the dorsal surface strongly convex and with a median thin, often depressed and pale strip (an extension of the dorsal suture) bordered by a pair of veins and reaching to the base; beak ± abruptly differentiated from the body of the perigynium, coarse, serrulate-margined, often pale or greenish; achene lenticular; 2n=60. Swamps, wet meadows, and Sphagnum-bogs; circumboreal, s. to N.J., Pa., Ind., Mo., Colo., and Calif.