Notes on Potentilla.— VI. 



By p. a. Rydberg. 

 (Plates 287, 288.) 



The Hippianae constitute a group somewhat related to the 

 Midtijugae. They are, however, as a rule stouter than the mem- 

 bers of that group, and the leaves are more or less white or gray- 

 ish hairy, generally densely silky, villous or tomentose. The 

 group contains the following species : 



Potentilla Breweri S. Wats. Proc. Am. Acad. 7 : 555. 1873. 

 Potetitilla Breiveri much resembles P. Plattensis. It has the 

 large stipules characteristic of that species and also essentially the 

 the same flowers. The leaflets are, however, broader and less di- 

 vided and densely silky-villous. In the typical form the cyme is 

 rather dense and the flowers larger. It grows in California. 



Potentilla Breweri expansa S. Wats. Bot. Cal. i : 179. 1876. 



Potejitilla Plattensis leticophylla Greene, Erythea, i : 4. 1893. 



This resembles P, Plattensis still more, having the open cyme 

 of that species. It grows also in Nevada and is apparently more 

 common than the species. 



Potentilla crinita A. Gray, Mem. Am. Acad. 1849: 41. 1849. 

 This is of similar habit but easily distinguished by its condu- 

 plicate, appressed-silky cuneate leaflets, which are slightly crenate 

 at the apex. P. crinita grows on the dry plains of Arizona, New 

 Mexico, southern Utah and Colorado. 



