BLACKTHORN 



119 



f~~J Drupe globoid, solitary, about 15 mm. 

 long ; flesh green, very astringent. 



Primus spinosa, L. Blackthorn (Fig. 113). The sharp 

 astringency disappears after frosting. Stone hard, slightly 

 flattened, about 10 x 8 x 5 mm., with irregular furrows 

 and ridges; kernel ovate pointed, with a velvety skin, 

 6x4 mm. 



P. insititia has a similar fruit, with sweeter flesh. 



Drupe oblong, slightly compressed and 

 grooved down one side, about 40 50 mm. 

 long ; flesh sweet. 



Fig. 113. Blackthorn, Prunus spinosa. 1, flowering shoot; 2, fruiting 

 branch; 3, flower in vertical section, enlarged; 4, fruit in section (Wo). 



