THE HORTICULTURAL SOCIETY OF NEW YORK 



C. Havemeyer, Emil L. Strobel, J. G. Webb, Wm. Fellowes 

 Morgan, Theodor A. Simon, Geo. T. Wilson. 



At the close of the business meeting, a symposium was held 

 on the Dahlia, opened by Dr. Britton with the following paper on 

 the origin of the name Dahlia, its relationship and distribution: 



The genus Dahlia was first described by Cavanilles in i/Qi, and dedi- 

 cated to Andreas Dahl, a distinguished Swedish botanist, who was born 

 in 1751 and died, while still a young man, in 1789; he was demonstrator 

 of botany at Abo. Dahl was evidently a prominent botanist of his time, 

 for Thunberg dedicated another genus to him in 1792, a Japanese relative 

 of the witch hazel. Dahl's botanical writings do not appear to have been 

 extensive, but he published in 1787 a work of forty-four pages, entitled 

 " Observationes botanicae," in which he discussed the Systema Vegeta- 

 bilium of Linnaeus published in 1784. 



In 1803, Willdenow proposed to change the name Dahlia to Georgina, 

 for reasons which have long since been deemed insufficient, and the Georgia 

 proposed by Sprengel in 1818 is also superfluous. The name Georgina is 

 the basis of the German name Georgine for these plants. 



The species first described by Cavanilles in 1791, and thus the type of 

 the genus, is Dahlia pinnata, and it is well illustrated on Plate 80 of his 

 •Icones. A number of subsequent names have been applied to this original 

 species, among them, Dahlia variabilis Desfontaines, which was evidently 

 given with reference to the great variability of the plant in size, leaf-form, 

 and color of the flowers. In the third volume of his Icones, published 

 1794, Cavanilles described and illustrated two additional species. Dahlia 

 coccinea and Dahlia rosea. In subsequent literature, over thirty different 

 names have been proposed for supposed species of Dahlias, but about two 

 thirds of these have proved to be the same as others, so that the actual 

 number of wild species known to exist is probably not over a dozen; they 

 are natives of the Mexican Highlands, extending into the mountains of 

 Guatemala and Costa Rica, and one from Colombia has been described. 



Alorphologically, Dahlia is most nearly related to Coreopsis, differing, 

 structurally, mainly in minute features of the appendages of the style in 

 the flowers of the disk; the relationship is so close in some species that 

 some botanists have proposed to include Dahlia in Coreopsis, but this is a 

 view which has not obtained any wide acceptance. An examination of 

 some of the herbarium specimens obtained from wild plants of Mexico, 

 herewith exhibited, will be of interest at this time. 



Dr. Britton exhibited plates of the original dahlia species, and 

 also herbarium specimens of several species. These were in- 

 spected with much interest. 



At the close of Dr. Britton's remarks Dr. H. H. Rusby gave a 

 lecture, illustrated with lantern slides, upon the home of the 



46 



