BLACKTHORN 157 



Yellow Tar, Yellow Fitchling, Lady's Fingers, Mouse Pea, Crawpea, 

 Tom Thumb Vetchling. 



ESSENTIAL SPECIFIC CHARACTERS: 



90. Lathyrus pratensis, L. Stem climbing, angled, not winged, 

 tendrils small, leaflets 2, narrow, lanceolate, stipules sagittate, as long 

 as leaflets; flowers yellow, veined, flower-stalk many-flowered, in 

 raceme, secund, hile small. 



Blackthorn (Prunus spinosa, L.) 



Preglacial, Interglacial, and Neolithic beds have yielded evidence 

 of the early occurrence of this plant in Britain. In its present distri- 

 bution it is confined to Europe, but the Bullace is found in Africa and 

 the Himalayas, both in the Warm Temperate Zone. In Great Britain 

 it is found south of Sutherland throughout the country, up to a height 

 of 1300 ft. in Yorkshire. It is met with in Ireland and the Channel 

 Islands. 



The Sloe is so common a wayside plant as scarcely to need descrip- 

 tion. It is found not only by the highway, with Spindle, Maple, Crab, 

 Hawthorn, Cornel, and Elder, but also in the hedgerows, in fields, and 

 in woods, forming dense brakes in the latter, or in the open, where the 

 Blackthorn blossoms make the otherwise dark growth of branches 

 quite white in early spring. 



As the Latin specific name indicates this plant is peculiarly spinous, 

 which separates it from P. instititia, where there are few spines. The 

 plant is a bushy tree with numerous interlacing branches, rigid. 



The Sloe has the shrub habit. It is small, rigid, much-branched, 

 the branches spreading, zigzag, spinous (hence spinosa], the spines 

 being arrested branches. The wood is hard and tough. The bark is 

 black. The leaves appear after the flowers. They are egg-shaped, 

 or oblong to lance-shaped, stalked, and vary considerably in form, in 

 the acuteness of the leaf, and in the length of the stalk. They are 

 downy below when young, later hairless, and are toothed. 



The flowers are white, J f in. across, shortly -stalked, the stalks 

 solitary or in pairs, hairless. The petals are inversely egg-shaped to 

 oblong, and vary in breadth. The fruit is a drupe, the flesh adhering 

 to the stone, round. When the carpel becomes the fruit the layers are 

 three, the skin or epicarp, the flesh or mesocarp, and the inner stony 

 endocarp, the three forming the pericarp, the seed being the kernel 

 within the stone. There are two ovules, one often being unde- 

 veloped. 



