This northern (circumboreal) species has been reported from Ky., but no verified coll. has been seen. B's coll. from MCRE (US), and others with this name, appear to be terrestris instead, but further checking may be needed. C. palustris is close to heterophylla but differs in its more elongated, ellipsoid fruits (versus obovoid or almost cordate); 2n = 20.