352 Rydberg: Notes on Rosaceae 



In the Gray's New Manual, published September 18, 1908, the 

 authors, Robinson and Fernald, stated under Potentilla Anserina 

 as follows: "Var. grandis T. & G. is merely a luxuriant state in 

 rich meadows." It is strange that so shortly after, in January, 

 1909, Professor Fernald should admit this variety as a good species. 

 The difference in the achenes, pointed out by me, evidently per- 

 suaded him that it could not be kept in Potentilla Anserina L. 

 {Argentina Anserina Rydb.). It would have been asking too 

 much if one expected him to admit all at once the eight species 

 recognized in my monograph. My intention is not to defend them 

 as species. The limitation between species and variety will al- 

 ways be arbitrary, so also between variety and form. If Professor 

 Fernald admitted Argentina argentea as a variety under the name 

 Potentilla Anserina var. sericea, he should have admitted A. 

 occidentalism A. litoralis, and A. subarctica also as varieties. There 

 are certain statements, also, in Fernald's article, to which I must 

 take exception. As Professor Fernald has admitted Argentina 

 argentea Rydb. as a variety I should feel content so far as this 

 species is concerned, but I can not pass it altogether. The speci- 

 men in the Gray Herbarium from St. John Valley, referred to in 

 Professor Fernald's paper is "in spite of its leaves being silvery on 

 both sides," not A. argentea. I remember the specimen very well. 

 Neither is A. argentea exactly the same as Potentilla Anserina 

 sericea Hayne. Both have leaves silvery on both sides, but in the 

 Rocky Mountain plant the leaflets as a rule are decidedly obovate, 

 with comparatively few ovate teeth, while in the Eurpoean plant 

 the leaflets are usually much longer, elliptic, and with numerous 

 lanceolate teeth directed forward. I have not seen any specimens 

 of Argentina argentea east of South Dakota. It needs therefore 

 not to be considered in connection with the flora of eastern 

 North America. 



In discussing the species with nongrooved achenes, Professor 

 Fernald criticizes my key, in which I separate P. pacifica and P. 

 occidentals s from the rest by the petals being " usually over 1 cm. 

 long rounded -obovate," while the others have petals "6-8 mm., 

 rarely I cm. long, usually elliptic-obovate." It may be true that I 

 have "never known the full beauty of its large flowers " [A . litoralis] 

 and that the given characters do not hold. I did not see the speci- 



