dental sources, I shall yet have occasion to allude to his very inte- 

 resting remarks on the habits of Rubi, which have appeared in the late 

 part of the 'Transactions of the Botanical Society of Edinburgh.' 



One of the greatest difficulties in this difficult genus, is the assign- 

 ing of the exact limits of species. There are often forms sufficiently 

 marked and constant to require a clear discrimination from others, 

 with which, however, they evidently occasionally osculate. They 

 cannot on this account be considered specifically distinct, and yet 

 there is an inconvenience in considering them mere varieties, because, 

 like true species, these again have variations of form which require to 

 be recognized. In the ' Manual of British Botany ' by my friend Dr. 

 Macreight, an attempt is made by the late eminent botanist, my la- 

 mented friend David Don, who, I am informed by the accomplished 

 author himself, supplied this genus for the Manual, — to get over this 

 difficulty, by distinguishing these forms as sub-species. This arrange- 

 ment has not been accomplished with so much accuracy as I should 

 have expected from one in general so accurate ; but it is not of the 

 execution of the task I now wish to speak, but of the principle, I 

 confess there appears to me something contradictory in the very name 

 of a sub-species ; and I would rather recognize those forms which are 

 really not species, as varieties ; and when these again contain forms 

 requiring notice, I would recognize and designate them as sub-varie- 

 ties* This appears far less objectionable, and would not very fre- 

 quently require to be made use of. 



It is almost universally believed of the Rubi, that they are plants 

 with perennial roots, producing biennial wood ; that the stems are, — 

 to use the words of Lindley, — " sterile the first year, bearing flowers 

 and fruit the second, and then perishing." f Even those close obser- 

 vers of these plants, the illustrious Weihe and Nees von Esenbeck, 

 were of this opinion,^ as well as all the authors of our various Floras. 



* Somewhat in the manner of Mr. Borrer's analysis of Rosa canina in Hooker's Flora. 



-j- Lindley's Synopsis, 1st. edition, p. 91. 



X These are the words of the learned authors on this point. " Rubi, cum aliis 

 plantis, his similibus, inter veras frutices, quorum caulis perstat, et plantas, perenni 

 radice instmctas, (seu caulocarpicas DecandoUii), medium fere locum occupant, cum 

 non nisi pars eorum ferat hyemem, omnisve, ut rem acu attingamus, surculus vitam 

 biennem expleat ; namque primo, quo surculi enati sunt, anno citissime crescunt, et 

 in eximiam longitudinem protensi, tandem ad lignosi fere trunci duritiem perficiun- 

 tur ; turn altero anno flores ferunt fructumque, his autem peractis, pereunt. Hinc se- 

 quitur, cuicunque Ruborum frutici duplices quasi ordinis surculos futures esse, quorum 

 alios hornotinos invenies atque steriles, alios autem biennes, floreque et fructu gau- 

 dentes." — Weihe et Nees, ' Rubi Germanici,' p. 3. 



