Carex haydenii Dewey. Section: [26r] Section 13 Phacocystis. Phen: May-Jun. Hab: Wet meadows, wet prairies, minerotrophic fens. Dist: NL (Newfoundland) and QC west to SD, south to s. PA, MD (C. Frye, pers. comm., 2000), IL, and IA.
Origin/Endemic status: Native
Synonymy: = C, F, FNA23, G, GrPl, Il, K1, K3, K4, Mi, Mo1, NE, NY, Pa, Mackenzie (1931-1935)