2s6 



MONO CO T YLED ONS. 



the flower is irregular (the parts of a set are different in size and shape) ; 2d, 

 adnation of all parts with the pistil; 3d, reduction and suppression of the 

 stamens ; 4th, the ovary is twisted half way around so that the posterior side 

 of the flower becomes anterior. Floral diagrams in fig. 328 show the posi- 



Fig. 328. 

 Diagrams of orchid flowers. A , the usual 

 type ; B, of cypripedium. (Vines.) 



Fig. 329. 

 Diagram of flower 



tion of the stamens in two distinct types. The number of orchid species is 

 very large, and the majority are found in tropical countries. 



500. Related to the orchids are the iris family, in which the stigma is ex- 

 panded into the form of a petal, and the canna family. In the canna the 

 flower is irregular (see figs. 467, 468) and the ovary is inferior. (See chap- 

 ter on pollination. Part III, for description of the canna flower.) 



