ON THE DUMETORUM GROUP OF RUBI IN BRITAIN. 153 



tal value as those I have enumerated, but I have thought it safer only 

 to describe at present those forms which I have seeu in a growing 

 state, not precluding thereby myself or others from adding hereafter to 

 this group. Indeed, in Mr. Baker's excellent series of dumetormn 

 occur some two or three forms, which T believe deserve a separate de- 

 scription, but which I only know from his dried specimens. T also 

 gathered hurriedly at Henfield, Sussex, during last summer, a Rubus 

 of this group in many respects new and noteworthy. The present 

 essay is, therefore, the very reverse of exhaustive, and merely a humble 

 and provisional attempt to advance the study, to improve the arrange- 

 ment, and to catalogue some either new or imperfectly-described mem- 

 bers of the dumetorum set. The present ambiguity and confusion 

 which envelope this group are the writer's apology for this attempt. 

 Dia(jnosis of the Plant as a whole. 



R. dumeioriim, Weihe et Nees, Rub. Germ. t. 45 A; caule arcueto- 

 prostrato subtereti sa:pe csesio-pruinoso glabro vel patentim piloso, 

 aculeis inaequalibus modice robustis supra basin cite dilatatis sparsis 

 vel numerosis, aculeis et setis glandulosis copiosis vel paucis munito ; 

 foliolis quinatis, iiTegulariter dentatis, dentibus deltoideo-cuspidatis, 

 lateralibus late fere imbricatis, terminali rotundato-cuspidato, infra 

 plus minus dense griseo- vel raro albido-pubescentibus ; paniculis 

 thyi'soideis ; petalis latis pallidis vel roseis, sepalis demum reflexis vel 

 ascendentibus apice vix foliaceo-elongatis ; stylis et staminibus fere 

 pallidis ; fructu driipellis paucis magnis iiTegulariter maturatis confecto. 

 Attempted Varietal Diagnosis. 



a. concinnus ; caule subtereti, pilis setis et aciculis raris, aculeis 

 modice validis sequalibus instructo ; foliolis subtus tomentosis, 

 magis regulariter quam in varietatibus aliis serratis; panicula elon- 

 gata, thyrsoidea ; sepalis plerisque reflexis ; petalis pallide roseis. 

 /3. tuberculatus ; caule subpiloso, aculeis crebris subaequalibus, setis 

 aciculisque inconspicuis parvis et sparsis munito ; foliolis dupli- 

 citer serratis, subtus sparsim et hand tomentosis ; panicula aperta 

 baud ad apicem foliosa ; sepalis fructui adpressis ; petalis roseis. 

 y. pilosus ; caule hirto et piloso, aculeis aciculis et setis densis in- 

 aequalibus minuto ; foliolis magis argute dentatis quam in varieta- 

 tibus aliis et subtus magis pilosis ; panicula ad apicem foliosa ; 

 sepalis fructui adpressis vel reflexis ; petalis latis albis. 

 8. diversifolius ; caule sparsim piloso, aculeis longis rectis com- 

 voL. vm. [may 1, 1870.] M 



