DRUPACE^ 



395 



to produce spurs (Fig. 165). Flower buds are, as a rule, on 



these spurs, one spur bearing from 2 to 20 buds. The spur 



may terminate in a leaf bud. However, in most plums, true 



terminal buds are seldom formed. In 



such cases, if the last lateral bud is a 



branch bud, this continues the growth 



of the branch in a straight line. The 



Hne between the two seasons' growths 



is not as sharp, in this case, as when a 



terminal bud develops. If the last 



lateral bud is a flower bud, the twig 



usually dies back to the lateral branch 



developed from the last branch bud. 



In all plums, the flower buds are lateral. 



Flower buds usually stand out at an 



angle of about 30°, while leaf buds are 



more appressed to the stem. 



Leaves. — The leaves of plums vary a 

 great deal in size, form, color, surface, 

 thickness, and margin. In some species, 

 the serrations are tipped by glandular 

 prickles. Stipules are present. The 

 leaves are convolute in the bud (Fig. 



lOl). 



Inflorescence. — The flower ^^ buds of 

 the plum, unHke those of the apple and 

 pear, bear only flowers. They may 

 break open before, simultaneously with, 

 or after the leaf buds. The flowers are 

 in fascicled umbels. The number of 

 flowers in the bud varies from one to five, two and three 

 being the most common numbers. 



Flowers. — The receptacle forms a hollow cup (Fig. 163). 



Fig. 165. — Twig of 

 Domestica plum 

 (Prunus domestica) . 

 {After Paddock and 

 Whipple.) 



