help resolve the question of species recognition in the 
genus. Nassonov’s study (1940) is of little use, as he 
mentioned no binomials. He primarily studied variation 
in crop plants (all C. sativa’), where he identified three 
basic types of stem structure. He did note that wild and 
cultivated forms of hemp could not be distinguished 
clearly on the basis of anatomy of stem and bast fibres. 
Wood features of C. indica and C. sativa listed in 
‘Table 1 are those commonly measured in comparative 
studies. They are all significantly different between the 
species with four at the 5% level and five at the 0.1% 
level! Additional differences in the axial and radial paren- 
chyma systems are noted in the text. Woods of the 
two species are qualitatively distinct for libriform fibres 
versus gelatinous fibres and for presence of crystals in 
wood rays. Many examples of the taxonomic signifi- 
‘ance of crystals in woods have been noted (Bailey, 1961: 
Chattaway, 1955-56). 
Although only one sample of each species is discussed 
here, the magnitude of differences between the two is 
impressive in a system as conservative as wood. In his 
exhaustive review on many aspects of wood science, Jane 
(1963) stated the following regarding taxonomic wood 
anatomy: 
Wood structure is probably more conservative than floral struc- 
ture, and specific differences, as determined by floral characters, 
are often not reflected in the secondary xylem. Indeed, it may 
be said that in general the distinguishing features of wood are 
at generic, rather than specific, level. 
Certainly, the plants used in this study are of the same 
genus, but it is my opinion that they represent different 
species. 
examination of woods from three additional collec- 
tions of North American C. sativa shows they are also 
distinct from the C. 7ndica wood sample. All vary from 
