Amazonia. Amazonian coca leaves are always finely pulverized 

 before use in contrast to other varieties in which the whole leaf is 

 chewed (Plowman, 1981; Schultes, 1981). 



Trujillo coca is classified as E, novogranatense var. trux- 

 illense, based upon its morphology, ecology and alkaloid and 

 flavonoid chemistry. It is, however, intermediate in a number of 

 characteristics between £. Coca var. Coca and E. novo- 

 granatense var. novogranatense and may represent a stage in a 

 linear evolutionary sequence between these two taxa (Bohm, 

 Ganders & Plowman, 1982). Trujillo coca is well adapted to dry 

 areas and shows remarkable resistance to drought. Today it is 

 grown only in the river valleys of north coastal Peru and in the 

 arid valley of the upper Rio Maranon, with one disjunct 

 population in northwestern Ecuador (Plowman, 1979b). It is not 

 found anywhere in a wild or feral state and must be considered a 

 true cultigen. Trujillo coca probably evolved under domestica- 

 tion from E. Coca var. Coca in the drier valleys of northern Peru 

 or southern Ecuador and only later diffused to coastal Peru. 



Colombian coca, £". novogranatense var. novogranatense, is 

 cultivated in both wet and dry areas in the mountains of 

 Colombia but, like Trujillo coca, exhibits tolerance to drought. 

 It is also identical to Trujillo coca in its alkaloid and flavonoid 

 chemistry (Bohm, Ganders & Plowman, 1982; Plowman & 

 Rivier, 1983). Unlike the other cultivated varieties, Colombian 

 coca is partially self-compatible and appears to be the evolu- 

 tionarily most derived species. 



Dating of the time of divergence of the species and varieties of 

 cultivated coca has not yet been possible. Application of 

 techniques of biochemical genetic markers may prove useful 

 toward this end but have not yet been investigated in Ery- 

 throxylunh A second approach, which has been useful in 

 unraveling the early evolutionary history of many domesticated 

 plants, is the study of dated archeological remains. 



ARCHEOLOGICAL COCA 



The early evolution of coca in light of archeological evidence 

 recently has been reviewed in detail by Plowman (in press). The 



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