CHAP. II.] POLYGONEiE. 423 



than the other, and each furnished with a 

 pair of large stipules. The flowers are male 

 and female ; the first consist of four sepals? 

 two of which are much longer than the others, 

 and a beard of anthers, with the filaments united 

 into one common stalk, and each anther contain- 

 ing two cells for pollen. The female flowers have 

 five sepals ; the lower part is thick and fleshy, 

 having three unequal wings. This part becomes 

 the capsule, and it is furnished with three stig- 

 mas, each of which has two curiously-twisted 

 lobes. The capsule when ripe has three wings, 

 one much longer than the others ; and it is in 

 three cells, each containing a central placenta 

 with a double row of seeds, which are covered 

 with a beautifully reticulated skin. 



ORDER CLVII.— POLYGONE^.— THE BUCKWHEAT. 

 This order comprehends the Rhubarb {Rhe- 

 um)^ the Dock (JRumex ohtusifolius) ^ Sorrel (JR. 

 acetosa), the Buckwheat {Polygonum Fagopy- 

 rum), Persicaria (P. orientale). Water-pepper 

 (P. hydropiper), Siud Knot-grass (P. aviculare) . 

 The leaves of these plants either sheath the 

 stem with the base of their petioles, or are 

 furnished with ochrese, that is, with stipules 

 which are joined together so as to form a kind 

 of purse or boot. The flowers are inconspicuous, 



