310 BLACKTHORN, ETC. 



with 3 folds and longitudinally striate 

 {Prvfnus). 



Flowers axillary^ single or in pairs, or 

 clustered. 



Jf Flowers on short pedicels., solitary or 

 in small tufts; white, about 10 15 

 mm. in diameter. Drupe with waxy 

 hloom. Leaves convolute. 



-^ Spinose shrub, flowering before the 

 leaves appear. 



Prumis spinosa, L. Blackthorn (Fig. 125). Thorny 

 shrub, the white flowers proterogynous and offering pollen 

 and honey. 



Flowers single, on short stalks from the axils of 

 the leaves, on the dwarf shoots so close together that 

 the flowers appear tufted; opening before or with the 

 foliage. Pedicel and calyx glabrous, green ; petals snow- 

 white, anthers yellow. Fruit shortly stalked, erect, sub- 

 globose, purple-black pruinose, with green and very 

 astringent flesh. 



-^-=- Thorns few or none; floivers larger, 

 and appearing after the leaves. 



8 Pedicels short and doiony. 



Primus spinosa, var. or sub-sp. insititia, has fewer 

 or no thorns, the flowers chiefly in pairs, on hairy 

 pedicels, larger, white, and opening later, with the foliage. 

 Fruit oblong, with sweeter flesh. 



8 8 Pedicels longer and glabrous. 



Primus spinosa, var. or sub-sp. domestica, has no 

 thorns, glabrous shoots, greenish-white and smaller flowers, 

 and fruit pendent on longer stalks. 



