THE DICOTYLEDONES 1777 



tropous ovules. The form of the fruit varies very greatly and serves as the 

 basis of classification within the family. 



Fig. 1667. — Myrtiis communis. Flowering 

 shoot. 



The Alyrtaceae are divided into two main groups according to the 

 nature of the fruit. 



I. Myrtoideae 



In which the fruit is a berry or more rarely a drupe. Many are of 

 economic importance as cultivated fruits. Myrtiis, Psidiiitn, Pimenta, 

 Eugenia. 



II. Leptospermoideae 



In which the fruit is dry and few are of economic importance on that 

 account. Eucalyptus, Metrosideros, CaUistemon, Melaleuca, Darwinia, 

 Leptospermum. 



The genus Myrtiis is represented by some seventy species, of which 

 M. communis is the best known, being extensively cultivated and long 

 naturalized in Europe. Most of the species are shrubs of tropical or sub- 

 tropical origin. 



The genus Psidium, with over no species, is found in America and the 

 West Indies. Many are cultivated in the tropics on account of their fruits. 

 P. gtiajava (Fig. 1668) is the Guava which forms a tree up to 30 ft. high. 

 The fruit is eaten and is largely used for the confection Guava jelly 

 and in cookery. P. cattleianum is the Strawberry Guava and grows in 



