2l6 



BEGONIACEAL. 



[chap. 



leaves, the succulent epidermis of the stem performing tlie 

 function of these organs. 



There are three principal modifications m the form of the 

 stem amongst the leafless Cactacece, viz. the Columnar, 

 the Globular, and the Jointed or Lobed. The Indian 

 Prickly Pear belongs to the last type. Note the gradual 

 passage from bracts to petals ; both sepals and petals, as 

 well as stamens, being indefinite. 



45. Natural Order, BegoniacecB. — The Begonia Family. 



Succulent herbs, with oblique, usually alternate, leaves. 

 Flowers unisexual. Ovary adherent, three-celled. 



Type — Begonia laciniata (or any other species of Begonia). 

 Herbs with alternate, stipulate, obliquely cordate, five- to 

 seven-Iobed leaves, and axillary, two-flowered peduncles 

 of pale-pink unisexual flowers. 



Observe the almost invariable obliquity of the leaves, 

 the midrib dividing them un symmetrically : the sinuous 

 stigmas : the forked placentas, with indefinite ovules. 



The species of this small Family nearly all belong to the 

 genus Begonia. They are very widely spread through the 

 tropics, excepting in Africa, where but comparatively few 

 species have been met with. Few species are applied 

 to any use, excepting for ornamental purposes, for which 



