Prunus.] ROSACEA. 139 



vaiieties, from the Bullace upwards to what may perhaps be considered as ihe 

 Wild Plum (P. domestica), or in a descending series to the common Sloe (P. 



xiyin.n9n\ 



^. In the field opposite Whitewalls faira, growing intermixed with the com- 

 mon form, Mrs. Penfold, 1842 !!! At Hill farm. Freshwater ? 



Flowers mostly but not always in pairs, frequently solitary, or even in fascicles 

 of 4 or 5 together. Drupes globular, bluish black, with a glaucous bloom, 9 or 

 10 lines in diameter, tolerably eatable when fully ripe, which they are earlier than 

 the common Sloe ; nucleus ovato-globose, strongly rugose, with a deep groove 

 along one-half of the commissure, and 4 or 5 converging furrows on the opposite 

 side, the 2 outer or lateral ones largest ; all often interrupted and ending in deep 

 cavities or perforations. 



A very perplexing species, by no means constant to the characters assigned to 

 it. Bark usually of a lighter colour than in P. spinosa, gray, reddish, or partly 

 light ash, slightly downy. The flowers are seldom produced until the leaves are 

 ready to expand, often not till the expansion is far advanced ; in P. spinosa the 

 blossoms usually cover the leafless spray, and are for the most part withered whilst 

 tho.se of P. insititia are in perfection. The flowers of the common Sloe are usu- 

 ally not more than half the size of those of the wild BuUace-tree, generally soli- 

 tary, with longer narrower petals ; the leaves too are much smaller and narrower 

 in comparison with their length. In my specimens of P. insititia gathered near 

 Ryde the leaves are nearly quite glabrous, and equally so on the upper and under 

 surfaces ; nor are the flowering branches always terminated by a thorn. The 

 flower-stalks in my Byde specimens are pubescent, an assigned marked of the spe- 

 cies amongst continental authors ; in P. spinosa and the intermediate form, P. coe- 

 tanea, I find the peduncles perfectly glabrous. In P. insititia, however, from Mers- 

 ley, near Newchurch, the peduncles are smooth and the styles more or less curved, 

 as in all our wild plums and cherries. Another intermediate form between P. 

 insititia and P. spinosa grows in the trench on the E. side of Carisbrooke Castle, 

 differing from the former in its smooth peduncles and rather smaller flowers, and 

 uniting the reddish bark of the Bullace with the very rigid and thorny habit of 

 the Sloe. So various indeed are the gradations between these two supposed spe- 

 cies and P. domestica, that it is often difficult to assign a name to many of them. 

 I have found the blossoms of P. spinosa in a few instances with two or three dis- 

 tinct styles at Hastings, where a large-flowered variety occurs uniting the aspect 

 of P. spinosa with the leaves and blossoms of P. insititia, and of which I have 

 specimens in my herbarium, but I have never seen fruit produced on it. Indeed 

 the flowers of P. spinosa itself are not always solitary, but often in pairs and even 

 occasionally fascicled, and all on the same branch. The petals are in P. spinosa 

 often as much rounded, the bark nearly as pale, and the leaves as ovate as in P. 

 insititia. From the above considerations it appears more than probable that the 

 idea of P. spinosa and P. insititia being mere varieties of the same species is a 

 well-founded one. Nor is this view of the subject weakened by the fact of P. spi- 

 nosa inhabiting countries where P. insititia is unknown, as in most parts of the 

 N. of Europe, or by their often growing side by side in similar circumstances of 

 soil and situation, for we find both these conditions fulfilled iu the three perma- 

 nent forms or races of Primula vulgaris, of whose absolute identity there seems 

 now no room to doubt. Koeh (Syn. Fl. Germ, et Helv.) says P. insititia has 

 drooping fruit (fruct. globosis nutantibus) ; in P. spinosa the fruit is erect, accord- 

 ing to the same author.* An inspection of the figures of P. spinosa and P. irisi- 

 titia in Eng. Bot. affords a convincing proof of the difficulty of expressing by any 

 delineation the distinctions between the two, and I heartily concur with Mr. Wil- 

 son in believing both these and P. domestica to be simple modifications of the 

 same species, of which P. spinosa is the typical form. The figure of this last in 



* My observations have confirmed this, but may not the greater weight of the 

 larger fruit of P. insititia be sufficient to account for its position ? 



