BOTANY. 



605 



Dicecia. 



Hexandria. 



Peutandria. 



Order seven is OCTANDRIA, containing dioecious 

 plants, the males of which have flowers furnished 

 with eight stamens. This is a very small order, con- 

 taining only the genus poplar. Four species are 

 natives of Britain, one of which, the white poplar, 

 grows to a very large size when standing in its 

 favourite soil, a moist peat earth. 



Dioecia. 



Enneandria. Octandria 



The eighth order is ENNEANDRIA, the male plants 

 of which bear flowers having nine stamens. This is 

 also a small order, containing only three genera, two 

 of which, the mercury and frog-bit, are British. The 

 third, triplaris, is an American tree, useful for its 

 timber. 



Dioecia. 



Dodecandria. Decandria. 



The ninth order is DECANDRIA, the male plants of 

 which have ten stamens. Another small order, con- 

 taining five genera, all of which are exotics. One of 

 the principal is the papaw, a large tree-like herb, 

 bearing bunches of fruit resembling melons, much 

 used in India. 



The tenth order is DODECANDRIA, the male plants 

 of which are furnished with twelve stamens. This 

 order contains six genera : among them we find only 

 one British, an aquatic, called the water-soldier. 

 Another is the menispermum or moon-seed, which, 

 with all the others, are exotics. 



The eleventh order of the class Dicecia is ICOSAN- 

 DRIA, the male plants of which bear flowers having 

 above twelve stamens inserted in the calyx. There 

 are only three genera, none of which are British ; in 

 botanical collections they are inmates of the hot- 

 house. 



Dioecia. 



The sixth order is HEXAXDUIA, dioecious plants, | Order twelve \3 POLYANDRIA, the male plants of 

 bearing male flowers, having six stamens. This order I which are furnished with many stamens, fixed on tne 

 comprises seventeen genera, among which are six 

 palms, some of them of stately growth, and highly 

 ornamental in their native countries. The genus 

 smilnx is also here, some of the species of which 

 yield medical drugs. The only British genus is the 

 black bryony. 



Polyandria. 



Icosandria. 



receptacle. This order contains seven genera, all ot 

 which are exotics. Here we find Cliffortia, a genus 

 common in our green-houses. Also cycas and zamia, 

 plants of curious habit, to be met with in most 

 collections. 



The last order of the class is MONADELPHIA, the 

 male plants of which bear flowers, in which the sta- 

 mens are united in one brotherhood. This order 



Dioecia. 



Monadelphia. 



comprises fifteen genera, of very various bulk and 

 manner of growth. Here are the magnificent Bour- 

 bon palm, the lofty and symmetrical araucaria, the 

 humble butchers' broonr the pyramidal juniper 

 the dark yew the fragrant nutmeg, and the curious 

 pitcher plant, forming together a most interesting 

 assemblage. 



The twenty-third class is POLYGAMIA, signifying 

 many marriages; that is, of plants having both 

 Polyttamia. unisexual and bisexual flowers 



on the same, or on different 

 roots. There is a good deal 

 of uncertainty about placing 

 plants in this division of the 

 system, because some of the 

 genera are not always con- 

 stant in their modes of flower- 

 ing ; and even single plants 

 will occasionally exhibit all 

 the characters by which the 

 different orders are founded. 

 This class contains sixty- 

 eight genera, and seven hun 

 dred and thirty-six species, 

 and is divided into two orders. 

 The first order is Mo- 

 Moncecia. NOECIA, containing plants in 



which the polygamy is complete on one root, that is 

 where there are male flowers having stamens only 

 female flowers having pistils only, and flowers in 

 which the stamens and pistils are united. This is a 

 very extensive order, and contains many highly 

 beautiful as well as useful plants. Here are the 

 mimosas, the ingas, the acacias, the maples, the beau- 

 tiful ailantus, and the fine fruit tree, the mango. 

 There are also a good many of the gramineae in this 

 order. 



