This widespread northeastern species is largely restricted to wetlands. It is relatively robust and rough-hairy, with distinctively hirsute pedicels, and it often has more divided cauline leaves, compared to canadense and virginianum. But its white petals are moderately short (mostly 3-5 mm), and its receptacles are less hairy. Most plants in Ky. are referable to var. trichocarpum Fern., with bristly achenes. The somewhat more northern var. laciniatum, with glabrous achenes, has been collected in BRAC and LEWI (NCU), but it is not clear if these taxa are worth separating (W).