202 CLASS TRIANDRIA. 



Fig. 104. 



Fig. 104, represents the Ixia (black 

 berry-lily) ; a, is an entire flower; b> 

 is the corolla cut lengthwise, to shew 

 the three stamens. The Ixia belongs 

 to the same family as the Iris and Cro- 

 cus. At c, is the flower of the mat- 

 grass (Nardus) ; having but one pistil, 

 it is separated from the grass family, 

 the greater part of which, we shall 

 meet with in the next order of this 

 class. 



Order Digynia. The Grasses. 



The 2d Order of the third class contains the family of the 

 grasses (Gramina) ; they are distinguished by a strait, hollow, 

 and jointed stem, or culm ; the long and linear leaves are pla- 

 ced at each joint of the stalk in alternate order, enclosing it 

 like a sheath. The flowers of the grasses are found in what 

 is called the ear, or head, and consist of two green husks, 

 called a glume ; within this glume calyx is the blossom, con- 

 sisting of a husk of two valves. These husks constitute the 

 chaff", which is separated from the seed by an operation called 

 threshing. 



These little flowers, which are also furnished with a nectary, 

 are green, like the rest of the plant, and you will need a mi- 

 croscope to view them accurately ; they are best observed in 

 a mature stage of the plant, when their husks, expanded, dis- 

 cover their three filaments, containing each a large double an- 

 ther ; their two pistils have a kind of reflected, feathered stig- 

 ma. They have no seed vessel ; each seed is contained within 

 the husks, which gradually open ; and unless the seed is gath- 

 ered in season, it falls to the ground. This facility for the 

 distribution of the seed is one cause of the very general diffu- 

 sion of grasses. 



The roots of grasses are fibrous, and increase in proportion 

 as the leaves are trodden down, or consumed ; and the stalks 

 which support the flower are seldom eaten by cattle, so that 

 the seeds are suffered to ripen. Some grasses which grow on 

 very high mountains where the heat is not sufficient to ripen 

 the seed, are propagated by suckers or shoots, which rise from 

 the root, spread along the ground, and then take root them- 

 selves ; grasses of this kind are called stoloniferous, which 



Explain Fig. 104 What family is found in the order Digynia ? Roots of 

 the grasses. 



