CANNABIS SATIVA 



2-17 



them may have a lateral spread of 80 cm. In the richer humus 

 soils where the main tap root penetrates less deeply, numerous lat- 

 eral roots are formed in the upper 10 to lo cm. of the soil; and the 

 root system is much more compact. 



The Inflorescences. — Hemp is dioecious, and the number of 

 staminate and pistillate plants is relatively constant under normal 

 conditions, the number of the former being somev^hat less than that 

 of the latter. Associated with the dioecious condition is a distinct 

 vegetative dimorphism which has been described by McPhee (xi). 

 The staminate plants are taller 

 and more slender than the car- 

 pellate, and the terminal stam- 

 inate inflorescences have few 

 leaves. The carpellate plants 

 are shorter and more stocky, 

 with a broad crown of leaves 

 associated with the terminal 

 inflorescence. (Figs. lox and 

 103.) 



Although hemp is dioe- 

 cious, it is not uncommon for 

 an individual plant to bear 

 both staminate and carpel- 

 late flowers. According to F.g. lox. Habit of staminate flowers of hemp. 



^ (Reproduced from Yearbook of U. S. Dept. of Agn- 



McPhee (xx), the occurrence „,/,^,,^ ^^.^ ) 

 of monoecious plants is more 



common when the daily exposure to light is short; and under 

 experimental conditions, it has been possible to modify and control 

 to some degree the production of staminate and carpellate flowers. 

 This does not seem to affect the vegetative characters, which 

 remain the same regardless of whether the plant is strictly 

 dioecious, or later becomes monoecious through the production of 

 both staminate and carpellate flowers. Schaffner (x6), as a result 

 of rejuvenation experiments, has reported that "sex reversal can 

 be successfully brought about during the second ontogenetic 

 differentiation cycle of rejuvenated plants in individuals that were 

 of pure sex expression in the first or natural differentiation cycle"; 

 and has suggested that "speculations as to the nature and fixity of 

 sex, especially in relation to heredity, are of questionable value, and 

 formulae based arbitrarily on the behavior of individuals during 



