TAXONOMY 269 
offensively smelling. Fruit a capsule. Seeds with copious albu- 
men and minute embryo. 
Official drug 
Part used 
Botanical name 
f Aristolochia 
Habitat 
Serpentaria 
Rhizome and roots 
1 Serpentaria 
I Aristolochia 
\ United States 
1 reticulata 
Asarum N.F. 
Rhizome and roots 
Asarum canadensis 
United States 
Pig. 138. — Serpentaria — -Cross-section of rhizome. (25 diam.) A, parenchyma 
of cortex; B, Medullary ray; C, xylem; D, phloem; E, medulla. (Sayre.) 
IX. Order Polygonales. — Polygonacece Family . — Usually herbs 
(Polygonum, Rumex, etc.) rarely trees (Coccoloba uvifera and C. 
platyclada) or shrubs (Muhlenbeckia, Brunnichia) having strong 
vertical tap roots and spreading secondary roots more or less pro- 
vided with tannin compounds. Stems elongate, green, to woody, 
rarely flattened, leathery, phylloidal (Muhlenbeckia platyclada) still 
more rarely tendriliform (Antigonum leptopus). Leaves alternate 
rarely opposite or whorled (Eriogonum), entire, rarely lobed (Rheum 
palmatum, Rumex acetosella), petiolate, rarely sessile, and stipu- 
late. Stipules fused and forming a greenish membranous upgrowth 
(■ ocrea ) which sheathes the stem. Inflorescence racemose with 
many dense scorpoid or helicoid cymes, which in some forms 
condense into single flowers. Flowers regular, pentamerous, 
with simple calyx becoming trimerous with two whorls of three 
