back 190 years to Lamarck’s recognition of a collection 
from India as distinct from the species which Linnaeus 
thirty years earlier had named Cannabis sativa. 
As an outcome of investigations carried out by Russian 
students of crop plant evolution in the 1920’s and 1980’s, 
the opinion that there are indeed several species of Canna- 
bis was, for the first time, offered on the basis of studiesand 
experience in the field. They are the only taxonomists 
to have studied extensively wild populations of Cannabis. 
Their work, however, has not been widely accepted. Fail- 
ure to accept or at least to consider seriously their opinions 
has been the result of several factors: partly because their 
work was published in Russian in journals of limited 
availability; partly because western botanists were not 
able to visit the areas of presumed wild Cannabis in Rus- 
sian territory; and perhaps most significantly because of 
conservative unwillingness to contemplate change in the 
established belief in the monotypic nature of the genus. 
We began to question the generally accepted view of 
Cannabis as a monotypic genus in 1969, when one of the 
writers (Schultes) was invited to address a symposium in 
London composed mainly of chemists and pharmacolo- 
gists. He was asked to address himself to what is vot 
known about the botany of Cannabis. Although, in that 
lecture, essentially a review of the literature, he clung to 
the idea of the monotypic nature of the genus, his evalua- 
tion of the limited taxonomic studies raised serious doubts 
in his mind about the propriety of this viewpoint (19). 
Subsequent critical studies of the literature ; examination 
of material from many areas preserved in several of the 
world’s largest herbaria; preliminary field work in Af- 
ghanistan; and a survey of the plantings of Cannabis in 
Mississippi from seed imported from many localities 
around the world under the auspices of the National In- 
stitutes of Health—all have combined to convince us 
[ 341 ] 
