270 
PHARMACEUTICAL BOTANY 
sepals each. Stamens varying from fifteen or twelve to nine or six 
more rarely to five, four, three to one (Koenigia), hypogynous, more 
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. 
Fig. 139. — Rhubarb (Rheum) flower, external view, median lengthwise section, 
and with perianth and stamens removed. (Robbins, after Liirssen.) 
Official drug 
Rheum 
Rumex N.F. 
£ Unofficial 
Bistorta 
Part used 
Rhizome 
Root 
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 ( Centrospernue ).- — Chenopodiacece or 
Goosejoot Family . — Usually herbaceous halophytes or shore growers, 
