433 



/'. ovina James Macoun, Can. Rec. Sci. 



The specimens from which P. diversifolia pimiatisecta were de- 

 scribed, viz: Watson's nos. 331 and 332 of the King Expedition 

 iUustrate, I think, not less than three different species. In the 

 Gray Herbarium, no. 331 is represented as it seems by a typical 

 F. Plattensis. This is doubtless the reason why Watson afterwards 

 transferred the var. piimatisecta to that species. No. 332, which 

 Watson, in King's Report, characterizes as an alpine more hairy 

 form, is there represented by a specimen of what James Macoun 

 describes as P. ovina. This may be regarded as the typical P. 

 pinnatisecta, as the other forms of the collection are already named. 

 In the Columbia Herbarium, no. 331 is represented by an un- 

 usually large form of P. pinnatisecta {P. ovina Macoun) and no. 

 332 by a depauperate specimen of P. Breweri expansa Wats. 



The main differences between P. Plattensis and P. pinnatuccta 

 are well pointed out by Prof. Nelson, /. ^., only that his character- 

 izing of P. Plattensis refers rather to the most common, more pros- 

 trate form with narrow segments, mentioned above, and that his 

 specimens representing P. pinnatisecta are unusually large, less hairy 

 and with longer segments than usual. The typical form is sub- 

 caespitose, seldom over i dm. high, with nearly leafless flowering 

 stems, smaller stipules than in P. Plattensis, and a densely hoary 

 pubescence, especially when young. It ranges from Colorado and 

 Utah to British America, and is a strictly alpine plant. 



POTENTILLA MILLEFOLIA n. Sp. 



Low, prostrate or spreading ; stems numerous from the caudex, 

 about I dm. long, few-leaved, only a little exceeding the basal 

 leaves, appressed-strigose, often sparingly so. Lower stipules 

 lanceolate and scarious and brown, the upper ovate-lanceolate, 

 acute or acuminate, green, often 2-3 cleft. Basal leaves pinnate, of 

 many pairs, sparingly strigose-ciliate, nearly as long as the stems; 

 stem-leaves much reduced. Leaflets divided nearly to the base 

 into linear subulate divisions, which therefore look as if verticillate. 

 Pedicels slender, 1-2 cm. long, in fruit abruptly reflexed below the 

 strigose-hirsute calyx. Bractlets and sepals lanceolate, acute, the 

 former slightly smaller. Corolla 12-18 mm. in diameter. Petals 

 obcordate, deeply notched, longer than the sepals. Stamens about 

 20. Achene smooth, with a slender filiform nearly terminal style. 

 (Plate 277, figs. 1-5.) 



