Some Families of Angiosperms 



537 



Rose family {Rosacex). This is a cosmopolitan family of loo 

 genera and more than 2000 species. It is notable because of the 

 large number of useful plants that are cultivated for their flow- 

 ers or fruits. Here belong the roses, spiraeas, cinquefoils, straw- 

 berries, raspberries, blackberries, pears, apples, cherries, and 

 plums. The receptacle of the flower is usually hollowed, so that 

 the five sepals and petals surround a cup in which the numer- 

 ous stamens and the five to many carpels are borne. In the 

 strawberry the fruit is the enlarged fleshy receptacle. 



The legume family (Leguminosae) . This is the second 

 largest family of flowering plants, and in the importance of its 

 food products is second only to the grasses. It includes 500 

 genera and not less that 12,000 species, some of which grow in 

 every climate and habitat. Most of the plants have tubercles 

 on their roots and are hosts to nitrogen-fixing bacteria. Here 

 are included the sensitive plants (Mimosa), the acacias, red buds, 

 locusts, peanuts, lupines, clovers, beans, peas, and soy beans. 



^i. i-orlion (,f a plaiU uf hairy vetch (Vicia). The papilionaceous llowers 

 identify it as a member of the legume family. The outer branches of the compound leaves 

 are tendrils, as in the pea. 



