April, 1922 sexual nature of twins of aris^ma 153 



character and developed at the same time. The plot containing 

 the twins w^as then treated for reversal to the female state by 

 an application of rich cow^ manure and abundant w^ater supply 

 during the entire spring and summer. The follow^ing spring 

 (1921) the twins had both reversed their sex completely and 

 were now- pure carpellate again. Examination of the under- 

 ground parts showed that the corms had separated, although 

 with the dead part still united. The twins were now of unequal 

 size and one was nearly a week earlier in coming out of the 

 ground than the other. 



AriscBma dracontiiim (L.) Schott. 



Some observations and experiments were also made on the 

 green-dragon. This species consists of normal monecious and 

 staminate individuals with occasional abnormal intermediates. 



10. A plant with dichotomous inflorescens. The spathe 

 ended in two separate points, the free points being one inch 

 long. The spadix was double but united except near the tips of 

 the sterile part. The entire double spadix was staminate. One 

 of the free sterile tips was five-eighths inch long and the other 

 seven-eighths inch. There was also some difference in thickness. 



11. A simple staminate plant was transplanted from the 

 woods with others in 1920 and treated for continuation of the 

 staminate condition. In 1921 it gave rise by dichotomy to 

 identical staminate twans. 



12. A pair of tall, robust twdns that looked like monecious 

 individuals, but both stalks were completely sterile, each hav- 

 ing a small, abortive structure where the infiorescencs should 

 have developed. They were still united on a single very large 

 corm. This corm was transferred to the experimental plots in 

 1920 and treated for reversal to the staminate condition by 

 reducing the root system and leaf surface decidedly. In the 

 spring of 1921 both came up as pure staminate shoots. One 

 came out of the ground a week earlier than the other. 



CONCLUSIONS. 



All of the twdn Arisasmas described above show-ed a remark- 

 able similarity in vegetative characters and w^ere exactly alike 

 in sexual expression. Since it has been established that the 

 sexual state of Arisaema can be changed at will by proper 



