POTENTILLA DISSECTA Pursh, Fl. Am. Sept. 355. 18I4.
P. diversifolia Lehm. Nov. Stirp. Pug. 2: 9. 1830.
It would be much better if Lehmann's name were used for this species, as this, without any doubt, belongs to it. As to P. dissecta Pursh, nobody seems to know absolutely what it is. Dr. Watson thought it to be the same as P. diversifolia Lehm. Lehmann had seen P. dissecta in Bank's herbarium, but thought that his P. diver s!folia was different. Not being able to settle the matter satisfac torily, the author thinks it best for the present not to make a change in the " accepted " nomenclature, although P. diversifolia is a good name, and available, and besides has the advantage of belonging to this plant without any doubt.
To the author it seems as if P. dissecta rather belonged to P. multzsecta (see below) or to P. Ranunculus. Lange's description and figure of the latter in Flora Danica, and the only specimen seen by me agrees much better with Pursh's description of P. dissecta than the present species does.
Dr. Watson included in his P. dissecta, with varieties, not less than five different plants, which I believe are all good species, viz.: P. diversifolia Lehm, P. decun-ens (Wats.), P. multisecta (Wats.),
P. pinnatisecta (Wats.) Aven Nelson, and P. Drunnnondii Lehm. These will be discussed further below. He also included P. Lehm.; I have not seen any authentic specimens of that. There are two forms that fairly agree with Lehmann's description and figure of P. rubncanlis. One differs from P. diversifolia Lehm. only in being smaller and with the leaves slightly whitened be neath. Following Gray and Watson, I have taken this to be P.
ntoricendis Lehm. and have made it a variety of the present spe cies. I regard the other form as a new species and it will be dis cussed later.
P. dissecta varies much in the form of the leaves. In the type of P. diversifolia Lehm. the lower leaves were pinnate with ap proximate leaflets, but all the leaves are as often perfectly digitate. The leaflets are larger than in the other related species, oblance olate, and generally seven in number. In the typical form they are generally appressed-hairy. All specimens seen are from the plain and mountain regions of the West, the range extending from Colorado to California, British Columbia and Saskatchewan.