CHAPTER XXVIII 



DRUPACE^ (Plum Family) 



Habit, Stems. — Representatives of the plum family are 

 trees or shrubs. The bark exudes a gum, and the leaves, 

 bark, and seeds are bitter, and contain prussic acid. Many 

 cases of poisoning have been 

 recorded from eating the seeds 

 of peach and bitter almond, and 

 it is also known that stock is 

 poisoned from eating the leaves 

 of wild cherries. The glucoside, 

 amygdaUn, acted on by emulsin, 

 an enzyme, in the presence of 

 water is changed to prussic acid, 

 grape sugar, and benzaldehyde. 

 Prussic acid is deadly poisonous 

 even in small amounts. 



Leaves. — The leaves are 

 alternate, petioled and com- 

 monly finely toothed. The 

 teeth and petiole are often 

 glandular (Fig. i6i); the stipules 

 are early deciduous. 



Flowers. — The perfect, regu- 

 lar flowers (Fig. 162) are 

 solitary (apricot), or in racemes (wild black cherry, etc.), 

 umbels (sweet cherry, etc.), or corymbs (perfumed cherry). 

 The calyx is free from the ovary, five-lobed, bell-shaped or 



391 



Fig. 161. — Leaf of peach 

 (Amygdalus persica). The base 

 of the leaf considerably enlarged, 

 in S. 



