322 



PHARMACEUTICAL BOTANY 



rarely by enlargement of receptacle and slight fusion of sepals, 

 perigynous. Pistil tri- to bicarpellate often three- to two-sided, 

 ovary one-celled with one ovule. Styles .three, rarely two, radiating 

 penicillate in wind-pollinated inconspicuous flowers, becoming con- 

 densed knob-like in conspicuous insect-pollinated flowers. Fruit a 

 triangular or biconvex akene often crowned by persistent styles and 

 surrounded by persistent closely applied sepals. Seeds solitary, 

 albuminous, with straight embryo, or in Rumex, curved embryo. 



PIG. 182. Rhubarb (Rheum) flower, external view, median lengthwise section, 

 and with perianth and stamens removed. (Robbins, after Lurssen.) 



Official drug 



Part used 



Rheum 



Rhizome 



Rumex N.F. Root 



Unofficial 

 Bistorta Rhizome 



Botanical name 



Rheum officinale 



Rheum palmatum 

 and the variety 

 tanguticum and 

 probably other 

 species 



Rumex crispus 



Rumex 

 obtusifolius 



Polygonum 

 Bistorta 



Habitat 



China and 

 Thibet 



Europe 



Europe and Asia 



X. Order Chenopodiales (Centrosperma). Chenopodiacea or 

 Goosefoot Family. Usually herbaceous halophytes or shore growers, 



