PHANEROGAMIA 



565 



The Myrtaceae are confined to warmer countries. Europe possesses the single 

 species Myrtus communis, the Myrtle. This family is especially characteristic of the 

 Flora of Australia, in which it forms the most striking feature as-regards the number 

 of species and individuals, including, in particular, the Eucalyptus tree, which 

 often attains a greater size than even the giant Conifers of California. Of late years 

 Eucalyptus trees have been largely planted in all warm, malarial countries. On 

 account of their wonderful rapidity of growth, they absorb large quantities of 

 water, and thus both drain the soil and purify the air. la the Tropics also, as 

 forest trees, the Myrtaceae occupy an important position. Many produce delicious 

 fruit, e.g. Guava, Psidium Guava. From other species spices are obtained. Cloves 

 are the flower-buds of Eugenia caryophyllata, a small tree indigenous to the 

 Moluccas, but cultivated in most tropical countries (Fig. 542) ; the stalk of the 

 clove corresponds to the receptacle of the flower. The fruit of another tree of the 

 same genus, E. Pimenta, is known as allspice. 



Officinal. — Caryophylli (Cloves), from Eugenia caryophyllata. 



Hysterophyta 



This group, which is merely provisionally established, includes 



Fig. 543.— Asanm ewopaeum. 1, Flowering shoot ; 2, flower cut through longitudinally ; 3, floral 

 diagram. (After Wossidlo.) 



chiefly plants that are parasitic, and which are on that account 



2 u 



