CLASSIFICATION OF ANGIOSPERMS. 525 



dark brown, cordate-winged, 3-angled akene. The dried root is 

 somewhat fusiform, reddish-brown, and with a bitter, astringent 



. Polygonacese), one of about 30 species 



taste. It contains chrysophanic acid, tannin, calcium oxalate, and 

 some of the other constituents found in rhubarb (Fig. 289). 



Rume.v Acetosella (field or sheep sorrel) is a slender annual 

 herb with hastate leaves, having flowers in compound racemes. 



