Sparganium eurycarpum Engelmann ex A. Gray var. eurycarpum . Hab: Marshes, shores. Dist: NS west to BC, south to w. VA, n. WV, IN, OK, CA and Baja California; e. Asia and Australia. Its attribution to more southern localities in North America by some older sources (such as FL according to Small) is believed to be in error.
Origin/Endemic status: Native
Synonymy: = K3, K4; = Sparganium erectum L. ssp. erectum – Cook & Nicholls (1986); = Sparganium eurycarpum Engelm. ex A.Gray ssp. eurycarpum – Mo1; < Sparganium eurycarpum Engelm. ex A.Gray – C, F, FNA22, G, Il, K1, Mi, NE, NY, Pa, S, Tat, Va, W, WV, Crow & Hellquist (2000b)