CONTRIBITTIOXS FROIM THE GRAY HERBARIUM OF HARVARD 

 UNIVERSITY, NEW SERIES, NO. XXXTT. 



STUDIES IN THE EUPATORIEAE. 

 By B. L. RoBixsox. 



Presented March 14, 1906. Received February 21, 1906. 



Introductory. 



During the summer of 1905 the writer spent some weeks in visit- 

 ing several of the larger herbaria of Europe in order to examine and 

 photograph plants not hitherto authoritatively represented in the 

 Gray Herbarium. In the course of this work considerable attention 

 was given to the tropical American species of the great genus Eupa- 

 torium and several allied genera. As must be expected in all such 

 large and difficult groups, which have not been subjected to recent 

 revision, the study of the type-specimens of several hundred species 

 has yielded much new information on the synonymy and proper classi- 

 fication of the group. The collections examined were : (1) the herba- 

 rium of the Museum of Natural History in Paris, where the herbaria 

 of Jussieu, Lamarck, and Michaux were consulted, and special atten- 

 tion given to an admirably preserved and well-nigh complete set of the 

 tropical American plants collected by Humboldt and Bonpland and 

 critically described by Kunth in the Nova Genera et Species ; (2) the 

 rich private herbarium of the DeCandolle family in Geneva, including 

 the invaluable Prodromus types ; (3) the herbarium of the Imperial 

 Museum of Natural History at Vienna, noteworthy among other ways 

 by containing the fullest series available of the species of Jacquin and 

 an excellent series of the plants of Pohl and species of Poeppig and 

 Endlicher; (4) the herbarium of the Royal Botanical Museum at 

 Berlin, remarkably rich in South American as well as in Old World 

 types and in the study of Eupatorieae specially noteworthy by ex- 

 hibiting to its fullest extent the recent critical work of Dr. Hieronymus ; 

 (5) Professor Urban's large and carefully selected West Indian her- 

 barium ; (6) the herbarium of the Botanical Museum of the University 

 of Copenhagen, containing, together with much other material of in- 

 terest, the extant types of Vahl ; (7) the herbarium of the Linnean 



