This variable species is widely scattered across most of temperate and boreal North America. All material from Ky. appears to be the southeastern var. harperi, sometimes treated as a subspecies or species. Var. harperi has perigynia 3.4-4.9 (5.4) mm long (versus 2.5-3.5 mm); achenes are more sharply angled; pistillate scales are more slender, more overlapping and whitish. However, the more widespread northern and western var. leptalea does extend south to Tenn. and N.C. in the Blue Ridge and Piedmont (W). These taxa may intergrade in some regions of overlap (FNA 23), and further analysis is warranted in Ky.