Rydberg : Notes on Rosaceae 489 



Dr. Wolf regards Potentilla ctenophora as a variety of P. 

 flabelliformis, which was also my first idea, before I knew the 

 plant better. Dr. Wolf makes some remarks which read in trans- 

 lation as follows: "The relationship of this variety to var. typica 

 seems to me about the same as, for instance, that of P. argentea 

 var. decumbens to its var. typica, and its elevation to specific rank 

 seems to have been made on slight grounds, as the author himself 

 in his monograph says that it should perhaps be regarded as a 

 variety of P. flabelliformis, as intermediate forms are not lacking. 

 Why has he not let it remain in its original category? It seems 

 that he makes the limitations of his idea of a species narrower as 

 the years pass by." This may be in a certain sense true, but it 

 has been brought about by a study of many years and the char- 

 acters stand out better and better as the plants become better 

 known. In this special case Dr. Wolf's remarks were more or 

 less amiss. I do not know what specimens he might have had 

 at hand to support his statements. Neither in the original descrip- 

 tions of P. flabelliformis ctenophora in the Bulletin of the Torrey 

 Botanical Club nor in my monograph, did I cite any specimens. 

 Unfortunately, I forgot to do so. The illustration in the mono- 

 graph gives only a basal leaf. There is nothing to show the 

 differences in general habit and the flowers. Professor Piper has 

 directed my attention to the fact that my P. ctenophora is the 

 same as P. Blaschkeana Lehm. Later he has also recorded his 

 views on this point in his Flora of Washington. I agree fully 

 with Professor Piper and have stated before that my conception 

 of P. Blaschkeana was a composite one, mainly made up of P. 

 grosse-serrata. Dr. Wolf, I think, did not make the same mistake, 

 for his description points unmistakably to P. Blaschkeana Turcz., 

 as described and illustrated by Lehmann, not as characterized 

 in my monograph. After the citation of Lehmann's plate, Dr. 

 Wolf gives in parenthesis "(optima)" '. His conception of P. 

 Blaschkeana was therefore evidently correct. As my P. cteno- 

 phora is evidently the same, why should it not be regarded as 

 specifically distinct from P. flabelliformis? 



Professor Aven Nelson in the New Manual of Botany of the 

 Central Rocky Mountains makes P. Blaschkeana a synonym of 

 p. gracilis and P. ctenophora a synonym of P. flabelliformis. 



