484 Rydberg: Notes on Rosaceae 



standing in the same relationship to D. Drummondii as D. octo- 

 petala ar gen tea Blytt stands to D. octopetala. This species has also 

 been collected in the Canadian Rockies, Macoun 65125. 



GEUM 



Geum vernum (Raf.) T. & G. was originally described as 

 Stylopus vermis Raf., and the writer is somewhat in doubt if this 

 species should not be regarded as the type of a distinct genus. 

 The habit is that of a typical Geum, but the receptacle in fruit 

 becomes stalked above the hypanthium, and the bractlets are 

 usually lacking. Occasionally, however, there are found minute 

 bractlets in this species, and the receptacle is more or less stalked 

 in Geum rivale. The generic characters of Stylopus do therefore 

 break down, and it is perhaps better to regard it a Geum, especially 

 as the general habit is not essentially different. 



Geum virginianum L. This species has in general been very 

 well understood. Murray, however, applied that name to G. 

 canadense and redescribed the true G. virginianum as G. laciniatum 

 Murr. Many have referred the latter synonym to G. canadense 

 and Scheutz suggests that it may be the same as G. agrimonioides 

 C. A. Mey., i. e. G. Meyerianum Rydb., but in my opinion it belongs 

 to G. virginianum L. 



Geum camporum Rydb. Some twenty years ago, the writer, 

 when working over the Rosaceae of Nebraska, had trouble in 

 determining some specimens of Geum, and did not know whether 

 to refer them to G. canadense or to G. virginianum. These speci- 

 mens had the thick leaves, the stout stem and branches, and the 

 large fruiting head of the latter, but the receptacle was not glabrous 

 and the achenes had the pubescence of G. canadense. When 

 working up the material for the North American Flora, he found that 

 the plant was more common in the prairie region of the Mississippi 

 valley than was expected and that its range extended from Minne- 

 sota and South Dakota to Arkansas and Texas. As both G. virgini- 

 anum and G. canadense are found in the region, G. camporum might 

 be regarded as a hybrid of the two. These two have about the 

 same distribution (except that G. virginianum is not found in 

 Mexico), but G. camporum is not found except in the western part 

 of their common range. It is, therefore, not probable that it is a 



