﻿Proceedings of the Club 213 



Kate's Mountain which find their nearest relatives on the Rockies 

 I 500 miles distant. 



Discussion followed on the respective value to be assigned to 



different characters. Dr. Britton held that absence of rays is an 



uncertain distinction in Senecio and that involucral characters are 



more permanent. The Secretary remarked on the failure ot 



acheneal characters in Aster, and Dr. Britton upon the same in 

 HeliantJius. 



Prof. Lloyd remarking that a priori we should expect to find 

 greatest variation in organs like leaves which are in direct contact 

 with their environment, Dr. Britton said that though leaves vary 

 much in form, they vary but little in assimilation-tissue, their 

 special character. 



Tuesday Evening, February 8, 1898. 

 Twenty-seven persons were present, President Brown in the 



chair. 



Asclepiad 



family. 



The first paper was by Dr. H. H. Rusby, describing " A new 

 Genus of Asclepiadaceae from Bolivia." Dr. Rusby discussed the 

 tribal and generic characters of that family, and exhibited speci- 

 mens of his new genus, which is a vine of vigorous growth and of 

 peculiar pollinial position. 



The second paper, by Miss Anna M. Vail, described a new 

 species of Aceratcs, or green-milkweed, with comparisons of the 

 other species already known. Specimens and illustrations were 

 exhibited, with remarks upon the history of the genus from its 

 earliest species, A. Floridana, onward. As distinctive characters of 

 Acer ates, she mentioned its aspect, its form of hood and its lack of 

 strong horn-like characters. The characteristics were further dis- 

 cussed by Dr. Edward L. Greene, who was present from Wash- 

 ington, and who emphasized the importance of its axillary sub- 

 sessile umbels and the green color in its flowers. 



The varieties of Aceratcs viridiflora were then discussed, 

 especially with reference to their great difference in leaf-form. 

 Miss Vail finds their flowers to be identical. Mr. Rydberg re- 



