INFLUENCE OF ENVIRONMENT ON SEXUAL 
EXPRESSION IN HEMP 
Joun H. SCHAFFNER 
(WITH PLATE XI AND ONE FIGURE) 
The study of hemp, Cannabis sativa L., was originally under- 
taken by the writer to determine what influence the environment 
might have on the sex ratio between staminate and carpellate 
plants. During the progress of the investigation, other problems 
in relation to sex presented themselves which were of more immedi- 
ate importance than the mere determination of the factors which 
might be the cause of variation in the expected number of staminate 
or carpellate individuals. The first plantings were made in the fall 
of 1913, but little was accomplished at that time because the 
department of botany was preparing to move into a new building, 
and, as is commonly the case in such ventures, several years were 
consumed in bringing the new plant into proper working order. 
The investigation was resumed in the fall of 1916, from which time 
on plantings have been made each year out of doors in the spring 
and each winter in the greenhouse, excepting the winter of 1917-1918, 
which was spent in Florida. 
As stated, it soon became evident that far more fundamental 
problems were presented for solution than the mere changing of 
sex ratios. Intermediate plants appeared, bearing both stamens 
and carpels. There was also an endless profusion of abnormal 
flowers involving all sorts of sexual expressions; and, most remark- 
able of all, complete reversal of sexual expression under the influence 
of an abnormal environment presented itself as the most interesting 
phenomenon to be studied. The last three years, therefore, have 
mainly been devoted to a study of abnormal flowers and sex 
reversal. 
Examination of the plants in the beds was pieaiky facilitated 
by the use of a Bausch and Lomb binocular magnifier. The 
rp the Dep t of Bot the Ohio State University, no. 120. 
r ‘~ 
{Botanical Gazette, vol. 71 
197] 
