494 Rydberg: Notes on Rosaceae 



has been the supposition that there are two species in the north- 

 west represented by Geitm calthifolium Menzies and Geum rotundi- 

 folium Langsd. It is evident that G. calthifolium Menzies de- 

 scribed in Rees' Cyclopedia was based on the plant known as 

 Geum rotundifolium. Scheutz seemed to be of a different opinion. 

 He kept Geum rotundifolium and G. calthifolium distinct. His 

 description of the latter (which by the way does not agree with 

 that in Rees' Cyclopedia) seems, however, to be drawn from 

 specimens of S. macrantha Kearney or some related species and 

 not from S. calthifolia. 



Sieversia macrantha Kearney. This species was distinguished 

 by Kearney and his description was found in the manuscript of 

 the Flora of Alaska, which has been in preparation for many years 

 by the botanists of the United States Department of Agriculture. 

 As there was no telling when this work would be published, I 

 adopted Kearney's name and description, with such slight modi- 

 fications in form as to make it congruous with the general style 

 used in the North American Flora. I have seen no specimens 

 except those of the type collection. It may be possible that 

 Scheutz drew his characterization of G. calthifolium from specimens 



of this species. 



ACOMASTYLIS 



As stated before, the writer agrees with Dr. Greene that the 

 specimens referred to it should be removed from Sieversia as well 

 as from Geum. They are closely related and the distinguishing 

 characters are rather trivial, but as these trivial characters are 

 supported by different ranges, the writer thinks they are of specific 

 value. 



Acomastylis humilis (R. Br.) Rydb. and A. Rossii (R. Br.) 

 Greene. The former seems sometimes to grade into the latter, 

 but as its range is much more limited than that of A. Rossii, it is 

 at least a geographical species. It is confined in America to the 

 Aleutian and Pribiloff Islands, but is also found in eastern Siberia, 

 while A. Rossii extends well into Arctic America as far east as 

 Melville Island. 



Acomastylis gracilipes (Piper) Greene and A. depressa Greene 

 are only known from the type collections. They are closely related 

 to A. sericea, but the hypanthium is more flat, not turbinate as i 



