138 MNNTAN ARTIFICIAL SYSTEM. 



Although the class Icosandria cannot be said to be a natural class 

 in the strict sense of the term, it nevertheless includes several great 

 assemblages of vegetables, which are related to each other by striking 

 family affinities. The great genus cactus, does not seem to have 

 much relation with the other genera. The genera pomegranate, 

 almond, cherry-tree, cocoa, plum-tree, pyrus and spiraea are re- 

 ferred to the natural order pomaceae. The principal genera of the 

 order polygynia are of the natural order srnticosce. The class 

 altogether is a very useful and innoxious selection of plants, scarcely 

 comprising one of a poisonous nature. 



73. The distinguishing; feature we have said of the 

 flowers of this class is, that the stamens are attached to 

 the calyx or corolla, and ncrer to the receptacle. 



This is a more certain guide than the number of stamens, which 

 is by no means constant, many flowers belonging to it possessing a 

 much greater number, and others, as tonnentilla, not so many as 

 twenty. 



74. Division : This useful and valuable class of 

 plants is divided into five orders ; viz, monogynia, <li.^>/- 

 itia, trigynia, pentagynia and polygynia ; all established 

 on the number of pistils in each flower. 



75. Monogynia: In this order are arranged those 

 plants of the icosandrous character, which produce 

 flowers with one pistil only. 



The most familiar examples of this order are the peach, plum, 

 cherry, common allspice, cactus, myrtle, pomegranate, almond, and 

 cocoa-plum-tree. 



70. Digynia: In this order we find such plants of 

 the class, as bear flowers with two pistils. 



The foreign genus waldsteinia, is said to be the only family 

 of plants, correctly of this order. 



