1916] HOAR—STERILITY IN RUBUS 383 
same as R. laciniatus Willd., with the leaves less cut. R. amnicolus 
Blanch. (fig. 8) is placed together with R. orarius Blanch. as a 
synonym for R. pergratus Blanch. 
Of those with a percentage of over 25 and less than 75 sterile I 
have R. frondosus Bigel., R. recurvans Blanch., R. glandicaulis 
Blanch., R. Jecklyanus Blanch., R. orarius Blanch., R. arundelanus 
Blanch., and R. amabilis Blanch. Of these Gray’s Manual cites 4 
as probably of specific rank, namely, R. frondosus Bigel. (figs. 9 
and 10), R. recurvans Blanch., R. glandicaulis Blanch., and R. 
Jecklyanus Blanch. R. orarius Blanch. is placed together with 
R. amnicolus Blanch. as a synonym for R. pergratus Blanch. R. 
arundelanus Blanch. is considered as a synonym for R. recurvans 
Blanch. Finally, R. amabilis Blanch. appears under the same 
name as R. canadensis L. Comment upon this group is unnecessary, 
unless to remark upon the apparent perplexity its members have 
caused systematists. Clearly from the standpoint of sterility much 
hybridization is now occurring and has already taken place. 
Of the last group, those with over 75 per cent of the pollen 
sterile, I have 4 specimens. These are R. biformispinus Blanch. 
(fig. 11), R. Andrewsianus Blanch. (fig. 12), R. tardatus Blanch. (fig. 
13), and R. peculiaris Blanch. These all seem to have distinctive 
form, and from the standpoint of the systematist may warrant a 
species rank, at least they are so considered in the Manual. How- 
ever, the pollen condition plainly points not only to hybridization, 
but to hybridization between species which must have been quite 
distinct and certainly quite incompatible. 
Besides these forms I have 1o or more which are not included 
with the range of Gray’s Manual. But one of these, R. deliciosus, 
(fig. 14), appears to be a good species when taken from the stand- 
point of absence of sterile pollen. I have R. caesus turkestanicus, 
R. corylifolius, R. spectabilis, R. plicatifolius, R. multiformis (fig. 
15), R. semierectus, and R. spectabilis plena (fig. 16). One of the 
forms, R. nobilis (figs. 17 and 18), which is known as a hybrid, is 
almost entirely sterile, and, as one would expect, contains but a 
very few grains which can possibly be considered as viable. 
Since my purpose has not been to attempt to place syste- 
matically the members of the genus Rubus, I have not given any 
