GAiMOPETAL^ 315 



regions. The Heath group is confined to Africa, the 

 Mediterranean region, and Europe. The Heaths are 

 social types, which have a typical growth-form, and 

 give their character to the physiognomy of a district. 

 Thus a heath may consist of Heaths entirely, and 

 the habit of the individuals is essentially alike. As 

 they grow in peaty soil, which is rich in humous acid, 

 they are adapted to physiological drought, already 

 explained. 



They are woody undershrubs, shrubs or trees, as in 

 the Strawberry Tree. 



In the Rhododendron group there are winter buds 

 even when the plants are evergreen. Scale leaves 

 cover the buds, which are deciduous. Terminal 

 rosettes of leaves are typical. The leaves are elliptic, 

 leathery, hairy, with a thick cuticle and water storage 

 tissue. In the Heaths there are no winter buds, and 

 they are evergreen ; the leaves are in whorls, and 

 hair-like, with the margin inrolled as in the Crow- 

 berry. 



The flowers are often solitary or in racemes, with 

 a bract and two bracteoles. They are hermaphrodite, 

 regular or slightly zygomorphic. The calyx is 

 superior or inferior, with four to five teeth or lobes. 

 The corolla is usually bell-shaped, hypogynous or 

 epigynous, with four to five teeth or lobes, rarely 

 . consisting of five petals. The stamens are eight to 

 ten, hypogynous or epigynous, in two whorls, the 

 outer opposite the petals, or shghtly epipetalous. 

 The anthers open inwards and are one- to two-celled, 



