ECONOMIC OR USEFUL PLANTS 415 



coca-butter, is used in medicine, and when removed from the 

 chocolate leaves coco, which for some persons makes a more 

 digestible beverage than chocolate. 



587. The tea family (Theaceae) is represented by the lob- 

 lolly bay, or tan bay (Gordonia lasianthus) , a tree with coria- 

 ceous evergreen leaves, and large, white, solitary flowers often 

 clustered at the ends of branches. The tree grows from West 

 Virginia to Florida in low woods, and flowers from May to July. 

 Franklin's tree (G. pubescens = Franklinia altamahd), a native of 

 Georgia, is cultivated as an ornamental tree as far north as 

 Massachusetts. The most important economic plant in the 

 family is the tea plant (Thea). Tea is a native shrub of sub- 

 tropical Asia. The dried leaves are used for making the well- 

 known beverage. It has long been cultivated in China and 

 Japan, and was introduced in cultivation more than a century 

 ago in Java, India and Ceylon. Attempts have been made to 

 cultivate it in South Carolina. 



588. The heath family (Ericaceae) .Examples are Labrador 

 tea (Ledum), in bogs and swamps in northern North America. 

 The azaleas, with several species widely distributed, are beau- 

 tiful flowering shrubs, and many varieties are cultivated. The 

 rhododendrons are larger, with larger flower-clusters, and are 

 also beautiful flowering shrubs. R. maximum occurs in the 

 Alleghany Mountains and vicinity, from Nova Scotia to Ohio and 

 Georgia. R. catawbiense, usually at somewhat higher eleva- 

 tions, occurs in Virginia and Georgia. The mountain laurel 

 (Kalmia latifolia) and other species rival the rhododendrons and 

 azaleas in beauty. The trailing arbutus (Epig&a repens), in 

 sandy or rocky woods, is a well-known small trailing shrub in 

 eastern North America. The sourwood (Oxydendrum arbo- 

 reum) is a tree with white racemes of flowers in August and 

 scarlet leaves in autumn. The spring or creeping wintergreen 

 (Gaultheria procumbens) is a small shrub with aromatic leaves, 

 and bright red, spicy berries. 



589. The huckleberry family (Vacciniaceae) includes the 

 huckleberries or whortleberries (example, Gaylussacia resinosa, 



