Teratology of Arisaema 



By Rosina J. Rennert 



Variations of form in the inflorescence of Arisaema triphyllnni 



have frequently been noted. Double spathes, which included a 



single spadix, were described by W. W. Bailey in 1884.* A 



curious case was reported by August F. Foerste who published 



an account f of a specimen of A. triphyllum which bore two leaves 



upon the same petiole. Arising from the axil of the double leaf 



was a double flowering stalk. The stems of the spathes w 



united below, but the spathes were separate and placed back to 

 back. Each had a perfectly normal spadix bearing ovaries. 



Double spadices also were described by Bailey. % The two 

 spadices were completely separate, in his specimen, only in the 



upper sterile portion. At the flower-bearing part, the two col- 

 umns were completely fused. One of the spadices was deformed 

 and much shorter than the other, being flattened below and dilated 

 at the tip. 



In Arum viaculatnm, a European aroid, similar monstrosities 

 have been noted by Masters and Braun. The former described a 

 case in which the spathe had taken the form of a stalked leaf.§ 

 In another instance the number of spathes was increased. || In 

 another the spadix was flattened, % and in a fourth case, a genuine 

 perianth was developed about the flowers on the spadix.** Braun 

 reported the occurrence of a branching spadix, and the multiplica- 

 tion of spathes in several instances, ft 



Dr. MacDougal has collected and grown several specimens 

 which illustrate variations in the inflorescence of Arisaema tri- 



* Botanical Gazette, 9 : 177. 1884. 

 t Botanical Gazette, 19 : 464. 1894. 

 % Bulletin Torrey Club, 9 : 91. 1882. 

 \ Vegetable Teratology, 245. 1869. 

 II Ibid., 358. 



H Ib 'd-> 3 2 9- 

 **Ibid., 225. 



If Verhandlung Bot. Vereins Brandenberg, i : 93, 95. 1859. 



247 



