TAXONOMY 



3 2I 



Official drug Part used 



Serpentaria Rhizome and roots 



Asarum N.F. 



Botanical name 



Aristolochia 



Serpentaria 

 Aristolochia 



reticulata 

 Rhizome and roots Asarum canadensis United States 



Habitat 



United States 



FIG. 181. Serpentaria Cross-section of rhizome. (25 diam.) A, parenchyma 

 of cortex; B, medullary ray; C, xylem; D, phloem; E, medulla. (Sayre.) 



IX. Order Polygonales. Polygonacea 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 sheaths the stem. Inflorescence racemose with 

 many dense scorpioid or helicoid cymes, which in some forms con- 

 dense into single flowers. Flowers regular, pentamerous, with 

 simple calyx, becoming trimerous with two whorls of three sepals 

 each. Stamens varying from fifteen or twelve to nine or six more 

 rarely to five, four, three to one (Kcenigia), hypogynous, more 



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