206 IMPORTANT FAMILIES OF PLANTS 



reaches its greatest perfection in China and in the United 

 States. The almonds (P. communis and P. nana) are closely 

 related to the peach ; and the nectarines are smooth-skinned vari- 

 eties of the peach. 



Plums also belong to the genus Prunus (P. domestica 

 Damson plum) and are also said to be of Asiatic origin, al- 

 though some botanists claim that they are indigenous to Europe. 

 The prunes' of commerce are varieties of plums which are espe- 



FIG. 130. Peach, an example of the stone fruits. The plum and cherry are other examples. 



cially well adapted to drying. There are also several species 

 of American plums. 



Cherries also belong to the genus Prunus and are well known 

 in both Europe and America. 



Raspberries, blackberries (Fig. 131) and dewberries belong 

 to the genus Rubus of the family Rosacese. In most cases there 

 are five petals and five sepals and many stamens as in the preced- 

 ing genera, but they differ from the preceding in having a num- 

 ber of ovaries which ripen into the well-known aggregate fruit. 



