CLASSIFICATION OF ANGIOSPERMS. 309 



tains a volatile oil, resin, a bitter principle and four alkaloids. 

 The wood of Amyris balsamifera of Guiana and Jamaica, yields 

 on distillation a volatile oil resembling Oleum Rhodii. 



h. SIMARUBACE^ OR AILANTHUS FAMILY.— The 

 plants are chiefly shrubs or trees with alternate and pinnately- 

 compound leaves. The flowers are regular, dioecious or polyg- 

 amous and in axillary racemes. The plants are natives of tropical 

 countries. 



Fig. 1S9. Quassia amara: A, flowering branch showing peculiar winged leaf stalk;. 

 B, flower-bud; C, the same after removal of the perianth; K, fruit. — After Engler. 



Picrasma excelsa is a small tree with 9- to 17- foliate leaves, 

 the leaflets being ovate and more or less tomentose, particularly 

 in the bud; the flowers are yellow, polygamous and in axillary 

 panicles; the fruit is a large, spherical drupe. The wood of the 

 plant constitutes Jamaica quassia (p. 544). 



Quassia amara is a small tree or shrub with 4- to 5-foliate 

 leaves ; the leaflets are narrow, obovate and acuminate, and the 



