in.] POLYGONACEAi. 269 



80. Natural Order, Polygonacece. — The Buckwheat Family. 



Herbs or shrubs, with alternate simple leaves, and sheath- 

 ing stipules. Flowers very small, ovary one-celled, with 

 three or two stigmas. 



Type — Polygonum barbahim. 



An erect, weedy herb, with alternate lanceolate leaves, 

 sheathing, coarsely -bearded stipules, and long, terminal, 

 spike-like racemes of inconspicuous, rose-coloured flowers. 



Observe the sheathing, membranous stipules character- 

 istic of the Family : the three-cornered, one-celled ovary : 

 trimerous symmetry of the flowers of Rhubarb {Rheunt) 

 and Dock {Rwiiex) ; the three inner perianth-leaves enlarged 

 after floMrering and adpressed to the ovary. 



A tolerably large and widely-spread Family. Many 

 species are weeds of both tropical and temperate countries. 

 A cUmbing Polygonum, the Buckwheat {P. Fagopyrum)^ is 

 grown in the Himalaya for its farinaceous seeds, of which 

 a good bread is made. The seeds of our Type are used 

 in Hindoo medicine. 



