54 



part hybridization may have played in the evolution of new moss- 

 species is at present premature. 



The hybrid which stands nearest to the one described above is 

 Aphanorhegma serratum 9 X Physcomitrium turhinatum ^ de- 

 scribed by Mrs. Britton from Drummond's specimens collected 

 near St. Louis.* Mrs. Britton also refers to the European 

 Physcomitrella patens 9 X Physcomitrium sphaericum cf , called 

 Physcomitrella Hampei by Limpricht (1885). It seems a ques- 

 tion whether the series of forms within which hybridization very 

 certainly occurs should not be regarded as falling within a single 

 natural genus, and I should be inclined to so include Physcomi- 

 trella and Aphanorhegma within Physcomitrium, over which 

 name Gymnostomum has priority, as Lindberg insisted. 

 Ithaca, N. Y. 



A NEW VARIETY OF RUBUS PARVIFLORUS 



By J. K. Henry 



^ RuBUS PA.RVIFLORUS Nutt. var. Fraserianus var. n. 



Distinguished from the species by having the petals laciniate- 

 dentate on their outer half. Ucluelet, Vancouver Island, 

 B.C.; June 19,1917,}. K. Henry; June 20, 1917, George Eraser. 

 These collections were made on both sides of Ucluelet harbor, 

 but Mr. Eraser, who directed my attention to this unusual form, 

 informed me that it is not common. As the plant has leaves 

 rather densely pilose beneath and the lower part of the sepals 

 hardly glandular, it might be considered a variety of Rubus 

 velutinus H. & A. {R. Nutkanus Moc. var. velutinus Brewer), 

 but it does not seem advisable to maintain two species. The 



* Bull. Torrey Club, XXII, 65 f. 1895. The differences hetweQu. Physcomi, 

 Irella patens, a plant of the three northern continents, and Aphanorhegma serralum- 

 which is peculiar to North America, are well brought out by Mrs. Britton in the 

 same volume, pp. 62 ff . with plates 229, 230. My observations are entirely in 

 agreement with her results, except that I find no incipient differentiation of a lid 

 in either European or American Physcomitrella and I do not find its stomata at all 

 immersed, but quite normal. 



