

CLASS DIANDRIA. 



197 



Fig. 103. 



plants. The distinguishing marks of this natural family are an 

 herbaceous stem, very broad leaves, a germ with three cor- 

 ners, and a liliaceous corolla. 



The red valerian (VALERIANA rubra), has but one stamen, 

 and might seem properly placed in this class, but other species 

 of this plant having three stamens, this one goes with the ma- 

 jority into the class Triandria. It is however not common for 

 different species of one genus to differ in their number of 

 stamens. 



Order Digynia, 



Contains an American plant, BLITUM, which is destitute of a 

 corolla. At fig. 102, c, is a flower of this genus ; its calyx is 

 deeply three parted ; it has no. corolla ; the germ resembles a 

 berry, and is crowned by two styles, which give the plant its 

 place in the order Digynia. - 



CLASS II. DIANDRIA. Containing three Orders. 

 Order Monogynia. 



This, though more extensive than 

 the class Monandria, is somewhat lim- 

 ited. We can however, without diffi- 

 culty, find examples for its illustration. 

 The Lilac (Syringa), is cultivated in 

 all parts of our country, and is ex- 

 ceeded in beauty by few ornamental 

 shrubs, in fragrance, perhaps by none. 

 The Corolla is salver form, or with a 

 'tube which spreads out into a flat, four 

 parted border. You might, at first 

 view, suppose the corolla to consist 

 of several petals, but if you attempt 

 to pull them out, they will all come off together, and you will 

 plainly perceive there is but one piece, or that it is monopeta- 

 lous. In flowers of one petal, the stamens are generally fas- 

 tened to the corolla ; where there are several petals, the 

 stamens are mostly attached to the receptacle ; this affords a 

 good mark of distinction between the two kinds of corollas. 

 You will perceive in the lilac, the two stamens standing oppo- 

 site to each other, and fastened to the corolla. The form in 

 which the blossoms are crowded together, forming a large 

 bunch, is termed a thyrse, which differs from a panicle, only in 

 having the spikes which compose it more densely crowded. 



Fig. 103, a, represents a flower of the lilac ; at 6, is the same 

 cut lengthwise, to show the two stamens. 



Diandria Lilac. 



17* 



