656 



1. Ccesii. — Having the barren stem round, bloomy, covered with unequal prickles, 

 trailing, rooting. Rubus csesius and its various derivations. 



2. GlanduloscE. — Barren stem angular, hairy and prickly, setose, very glandular, 

 arched or trailing, rooting. This group will include R. radula of Weihe and 

 Nees, R. Koehleri, fusco-ater, &c. 



3. Villicaulce. — Barren stem angular, very hairy, but without glands, prickly, arch- 

 ed or decumbent, rooting. Including R. villicaulis, W. & N., R. leucostachys, 

 Smith, &c. 



4. Fruticosi. — Barren stem angular, glaucous, prickly, arching, rooting. Including 



R. fruticosus and discolor. 



5. Nitidi. — Barren stem angular, almost smooth, wiih few prickles, rooting rarely. 



R. affinis, nitidus, rhamnifolius, &c. 



6. Suberecti. — Barren stem angular, very smooth, nearly erect, not rooting. Includ- 

 ing R. suberectus, Anderson and Smith, R. plicatus, W. & N., and R. fissus, 

 Lindley. 



7. Idwi. — Barren stem round, downy, covered with innumerable, small, dilated 



prickles, erect. R. Tdaus and varieties. 



There is, however, it must be admitted, an anomaly in the first group, which can 

 only be got over by subdividing it into two (as done in the tabular view), for the ex- 

 cessively glandulose assurgent stem of Rubus dumetorum has a very different aspect 

 from the prostrate bloomy one of R. csesius ; and yet it is demonstrable that the former 

 is really derivable from the latter: so that although the blue berries of the dewberry 

 would at first sight appear so discriminative, varieties arise with fruit altogether of a 

 different aspect. It must be borne in mind, however, that this is in a great degree in 

 accordance with the well-known laws of cultivation. Rubus dumetorum is R. cassius 

 excessively developed in leaves and flowers y'hnt the fruit is mostly abortive or imper- 

 fect, while R. csesius, in its normal prostrate form, with thin foliage and small flowers, 

 produces on the humid ground the finest fruit of any of the fruticose Rubi. 



The first group — Cassii — must therefore be necessarily divided into two-, but the 

 other groups will be found to maintain the characters assigned them pretty correctly, 

 and may therefore be depended on. It is true that occasionally some of the Villicau- 

 lae will exhibit a few glands on their stems or panicles, under circumstances of great 

 luxuriance of growth or exposure, but nothing to be compared with the excessive de- 

 gree of glandulosity of the Glandulosas. Then it is true that the barren stem of the 

 second group of Caesii is nearly as glandular as in the Glandulosae, but the former will 

 show their aflanity with R. csesius by the calyx being involute on the fruit, not reflex as 

 in the latter. 



The Fruticosi always preserve an independent marked character ; and the Nitidi, 

 if, in one of their forms — R. affinis — coming near to the Suberecti, may yet be always 

 well distinguished by the arching barren stem, which, when exposed, is very stiff and 

 rigid in the latter, almost as much so as in R. Idseus. This is well observable in the 

 barren moors of North Wales. 



Sketches of the barren stems of the different groups were exhibited. That the 

 forms of each group sport into each other according to situation and exposure, without 

 much limitation, is highly probable, but Mr. Lees had met with no decided cases of 

 hybridity. Specimens of various species accompanied the paper, and are deposited in 

 the Society's herbarium. — G. E. D. 



