264 CLASS MON(ECIA. 



%-' > 



Polyandria. 



This order contains many of the most useful and beautiful 

 of our forest trees, forming a group or family called Amentacea ; 

 this was described under the 15th class of Jussieu's method. 

 Fig. 123, represents a branch of the Corylus (Hazel-nut) ; at 

 a, is the aments or catkins formed wholly of staminatc flowers; 

 at , is a bract or scale of the ament with adhering stamens ; 

 at c, are the pistillate flowers surrounded with scales ; at d, is 

 a pistillate flower, having two styles. 



The oak, beech, walnut, chesnut, birch, &c. bear their 

 staminate flowers in nodding aments ; their pistillate flowers 

 are surrounded with scales for calyxes. These trees are dis- 

 tinguished by woody, exogenous stems, and perennial, branch- 

 ing roots. 



This order contains the genus CALLA, of which we have 

 some native species, and which includes the elegant exotic, 

 CALLA etJtiopica, or Egyptian Lily. In this genus, the flowers 

 having neither calyx nor corolla, grow upon that kind of recep- 

 tacle which is called a spadix ; the staminate and pistillate 

 flowers are intermixed, the anthers have no filaments, but are 

 sessile or fixed upon the receptacle ; the berries are one celled, 

 many seeded, and crowned with a short style. This spadix 

 thus covered with the fructification, stands erect, surrounded 

 by a spreading, ovate spatha ; this, in the Egyptian Lily, is of 

 a pure white, presenting a very showy appearance. Without 

 attention to the structure of the plant, you would probably sup. 

 pose the spatha to be the corolla ; the leaves are sagittate or 

 arrow form. 



Fig. 124. 



J 



The CALLA palusirisf a 

 very common American plant, 

 is represented at Fig. 124 ; at 

 a, is the spatlia, which is ovate, 

 cuspidate and spreading ; at b t 

 is the spadix covered with the 

 fructification, the staminate and 

 pistillate flowers being inter- 

 mixed and uncovered ; at c, is 

 a pistil magnified, showing the 

 c style to be very short and the 

 stigma obtuse ; at d, is a stamen 

 bearing two anthers. 



* From poZiwter, signifying swampy, or growing in marshy places. 



Order Polyandria Amentace Genus Calla Calla ethiopica Calla pe- 

 lustris. 



