Rather common in ditches and borders of streams from the Atlantic to the Pacific. It varies greatly in the form of its leaves, but the varieties are not recognized. Windsor, Grand Lake. Halifax, Pictou, and Truro, N.S. (Sommers, Cat.) Common in wet places, N. B. (Fowler, Cat.) Abundant throughout Quebec and Ontario, and extending westward to British Columbia. On the prairie region its leaves often become linear, and float on the surface of the still brooks south of Battleford.
We have doubtfully referred the A. natans, Pursh, to this species, as from the meagre description it seems to belong here. It was gathered in "stagnant waters of the St. Lawrence" by Pursh himself.