Much like P. flabelliformis, but the lfls shallowly and obtusely serrate, and sometimes closely crowded-pinnate instead of strictly palmate; 2n=56-108. Similar habitats; s. B.C. to Nev., e. to Man., ne. Minn., and S.D.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
