494 RybDBERG: NOTES ON ROSACEAE 
has been the supposition that there are two species in the north- 
west represented by Gewm calthifolium Menzies and Geum rotund1- 
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. calthifoliuni 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 1 
