THE RIBGRASS TRIBE. 209 



are white and green, disposed very closely in a 

 long spike, and remarkable for their long stamens, 

 the filaments of which soon become too weak to 

 support the heavy anthers. Each flower has a hol- 

 low bract on its outside {fig. 2. h.\ and a calyx of 

 four green sepals, which are also concave, and overlie 

 each other very much at the edges. The corolla is a 

 thin, almost transparent, greenish- white body , divided 

 at the end into four lobes {fig. 2. c.) which fall back 

 on the sepals. Four stamens arise from the tube of 

 the corolla, bearinsf on their filaments inverted 

 arrow-shaped anthers. The ovary {fig* 6.) contains 

 two cells, in each of which are many seeds {figs. 7, 

 8.), but it terminates in a simple hairy stigma ; on 

 this account it is considered to be formed of a simple 

 carpel, notwithstanding its two cells. In the course of 

 time, the receptacle of the ovules separates from the 

 sides of the ovary, and becomes covered all over with 

 seeds of a pale chesnut colour {fig. 10.) ; at the same 

 time the style drops off* the ovary, which changes to 

 a little hard dry brown case or capsule {fig. 9.), sur- 

 rounded with the sepals, and separating transversely 

 into two parts, by giving way at its base. 



These characters entitle the Ribgrass to be con- 

 sidered the representative of a very distinct, although 

 very small natural order, called the Ribgrass tribe; 

 which is, however, of too little importance to make 

 it worth detaining you longer about it. 



Now let us again consider the most essential distinc- 

 tions of the Monopetalous orders, I have recommended 



p 



