A contribution to the taxonomy of thePotentilla pensylvanicacomplex in North America

摘要

Investigation of this complex has revealed in North America the presence of three chromosome numbers, 2nensp;=ensp;14, 2nensp;=ensp;28, and 2nensp;=ensp;56. The latter two are widespread and correspond to the previously recognized speciesP. pensylvanicaL. andP. bipinnatifidaHook. The diploid, which is rather local in distribution, compares well with the description ofP. atrovirensRydb. and has on occasions been determined as such. The type specimen ofP. atrovirensis, however, clearly a form ofP. pensylvanicaand the diploid has never received formal taxonomic recognition. It is described here and namedPotentilla finitimaKohli and Packer n.sp.