that Cannabis is not monotypic and that the Russian 
concept that there are several species may be acceptable. 
It is not only the Russian sources (10, 29, 80, 31) that 
accept the polytypic concept of Cannabis. The British 
taxonomists who are editing ora Huropaea (28) clearly 
indicate their belief that two species occur within the con- 
fines of the floristic area which they consider Europe. 
Although they have not published their opinions, several 
American taxonomists who have examined the evidence 
likewise favor the polytypic concept. 
Other botanists who still maintain the monotypic na- 
ture of Cannabis are receptive to the possibility that con- 
tinued study may indicate more than one species. After 
a careful taxonomic evaluation of Cannabis on a generic 
basis, for example, Miller (14) suggested that only addi- 
tional investigations could clarify the variability in char- 
acters on which several species have been set up. And 
Small (22), who has carried out extensive cytological 
research on Cannabis, has stated that... “‘there would 
not appear to be a basis for recognizing species or other 
taxonomic groupings in Cannabis on the criterion of 
breeding isolation... [that ] some of the numerous taxo- 
nomic entities that have been recognized ... may be 
justified on the basis of morphological ground but, as no 
comprehensive morphological study of Cannabis has yet 
been published, all recognized taxa in Cannabis must be 
viewed with suspicion at present.” 
A complete clarification of the biology and systematics 
of Cannabis will, of course, require extensive field studies 
in those areas of Asia where the genus is presumably 
native or at least has not been subjected to intensive 
agricultural influence. Sufficient research has not been 
carried out to establish all of the general trends in the 
specific delimitation of the genus. Important aspects still 
remain unclear. Whether there are two or three—or 
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