Segregates of this widespread eastern annual are not well understood; 2n = 32 and 36 (FNA 5, W). Further review of colls. across the state is needed to assess the degree of distinction. Colls. from BUTL, FLEM and MADI have been referred to var. paleacea Fern. BA reported P. montana (Small) Pax & K. Hoffmann (= P. fastigiata var. pumila (A. Wood) Fern.), based on a misidentified coll. of typical fastigiata from MARS (WK).