The common commercial variety of dioecious hemp, Cannabis saliva when grown under favorable conditions is known to exhibit not only sexual dimorphism but certain other fairly uniform structural characteristics. Plants of the two sexes are distinguished by difference in the rate of growth, habit, and time of flowering. Certain characteristic vegetative traits such as the transition from three to five to seven compound leaflets and a modification in habit from opposite to alternate phyllotaxy, not usually correlated with sex, normally also occur with great regularity at certain stages of growth. An experiment was undertaken to determine possible variations produced in the normal expression of these vegetative traits and the usual sexual dimorphism by growth conditions varying from favorable to relatively adverse. Responses studied were the normal sequence of five to seven leaflets, opposite to alternate phyllotaxy, anthesis subsequent to the inflexion in rate of stem elongation, and whether this normal sequence could be altered; the differences in the growth responses induced by aeration of substrate under conditions of high and low nutrition; the effect of these two nutritional levels upon the most conspicuous changes (flowering, phyllotaxy, and five to seven leaflets) and the relation of the foregoing to periods of maximum growth.
Proceedings of the Iowa Academy of Science
©1951 Iowa Academy of Science, Inc.
Weber, John R.
"Nutrition and Aeration in Relation to the Growth of Cannabis saliva,"
Proceedings of the Iowa Academy of Science, 58(1), 221-228.
Available at: https://scholarworks.uni.edu/pias/vol58/iss1/24