CLASS TETRANDRIA. 



143 



corollas ; they are oblong and acute ; c, represents the stamens, 

 which are three in each flower ; the filaments are of the length of 

 the corolla ; the anthers are two-forked or bifid; d, is the pistil, hav- 

 ing an egg-shaped germ, and two spreading and feathery styles ; at 

 e, is the seed, not having any proper pericarp, but enclosed by the 

 two scales of the corolla ; it is single and naked. 



Fig. 125 shows the orchard-grass, of its natural size ; a, is the 

 stem, which is a cyhndric and jointed culm. At b, is the leaf, which 

 is long, narrow, pointed, simple, and entire. At c, are the flowers, 

 which are thick, panicled, and terminal. 



The orchard-grass is very common in the New England and Mid- 

 dle States. 



Of all the grasses, the darnel (Lolium) only is poisonous; this 

 plant seems to have been known in the days of Virgil, who, in his 

 " Pastorals," represents the shepherds as speaking of the lolium as 

 destructive to their flocks.* 



CLASS IV. — TETRANDRIA. 



The same number of stamens are found 

 in the plants of this class, as' in those of the 

 13th class, Didynamia. In the fourth class, 

 the stamens are of equal length, but in the 

 13th, they grow in two pairs of unequal 

 length. In this class we meet with no large 

 ^** 'o*-^^^' natural family ; the genera which compose 

 it appearing little united by natural relations. 



Order Monogynia. 



As an example of this order, may be men- 

 tioned the HousTONiA ccBrulea, which is known 

 by different common names ; as Innocence, 

 Venus^s Pride, and Blue Houstonia. It is a 

 very delicate little flower, appearing early in 

 * See Appendix, Plate iv. Fig. 6, for a representation of one of the grass tribe. 

 What does Fig. 125 represent 7— Which of the grasses is poisonous ■?— How doea 

 the fourth class agree with, and how differ from the 13th class 7— Houstonia. 



