NOTES ON BRITISH RUBI 131 



that those given for the rare species accord with suggestive fre- 

 quency (I think) with those of the commoner species which they 

 most resemble. 



I may say a few words on what have appeared to me reliable or 

 fallacious signs of specific difference among Eubi. No one who has 

 observed them much can have failed to notice how much the leaves 

 vary, not only in the same Rubus, but even in the same plant. 

 This may be well seen in R. Idaus. Luxuriance makes the leaves 

 larger, and especially wider, and the serration coarser. Leaves 

 may be ovate or obovate in accordance with the vigour or want of 

 vigour in a Rubus. Felt is a somewhat uncertain thing, its deve- 

 lopment being apt to fail if the bush or a part of it grow in the 

 shade. 



The colouring of the prickles where the sunshine can reach them 

 appears to me to be remarkably uniform in each Rubus, and well 

 worthy of notice in determining the species. 



In species in which the sepals become erect, this fails to happen 

 when fertilization of the carpels does not take place (often, if not 

 always). 



The comparative prominence of the stamens and styles is an 

 uncertain thing (as it seems to me), depending upon the luxuriance 

 of the plant ; when this is high the stamens (and petals too) being 

 longer. The hairiness or hairlessness of the petals is sometimes a 



valuable distinction. 



Having made these general comments on the Rubi, I now 



venture some on a few individual Rubi : 



R. Idjeus L. The distinctive characters of the var. asperrimus, 

 besides its crowded aciculi, or prickles, seem to be smaller size, 

 tortuosity of the stem, greater hairiness, no acuminatum to the 

 leaves, which are much more rugose, and yellow fruit. The colour 

 of the prickles may be either "tawny," drab, or purple. It is 

 undoubtedly wild on Tunbridge Wells Common, which is really 

 a moor, 



R. fissus Lindl. and R. suberectus Anderson seem to me very 

 doubtfully distinct. Plants in which some of the supposed dis- 

 tinctions of one are combined with those of the other are found. 

 Mr. Moyle Rogers asserts that Jissus becomes like R. suberectus in 

 damp places. The asserted differences between the two are just 

 those that occur with many another Rubus when it grows in a dry 

 sunny place and when in a damp shady one. 



M. Sudre points out that Hall's description of his nessensis will 

 apply equally well to either Jissus or suberectus. The specimens of 

 them in the " Type Set of British Rubi M do not seem to make the 



distinction clear. 



If the specimens of R. suberectus aud R. Jissus in the national 

 collections are examined, it will be seen what difficulty there has 

 been, and what uncertainty after all, in deciding to which species 

 some of them belong. In the Handbook there is also a plain 

 intimation that the same difficulty will occur. The same remarks 

 will apply to the distinction between R. sulcatus, on the one hand, 



l 2 



