STUDIES OF SOUTH AMERICAN SENECIOS— I l 



J. M. GREENMAN 



Curator of the Herbarium of the Missouri Botanical Garden. 



Professor in the Henry Shaw School of Botany 



of Washington University. 



The representation of the South American flora in American 

 herbaria has been greatly augmented during the past ten years 

 by several scientific expeditions to South America and by ma- 

 terial acquired from botanical correspondents and experienced 

 collectors residing in South America. 



Dr. N. L. Britton, Director of the New York Botanical 

 Garden, has generously submitted to the writer for study the 

 extensive suite of specimens of Senecio, collected in Colombia 

 by Dr. H. H. Rusby and Dr. F. W. Pennell in 1917 and 1918; and 

 Dr. J. N. Rose, of the United States National Museum, has 

 placed in my hands the excellent series of specimens of this 

 genus obtained by him and his associates on the several ex- 

 peditions to South America in connection with his studies of the 

 Cactaceae. Dr. B. L. Robinson, Curator of the Gray Herbar- 

 ium of Harvard University, Mr. William R. Maxon, of the 

 United States National Herbarium, and Dr. Charles F. Mills- 

 paugh, of the Field Museum of Natural History,, have kindly 

 loaned valuable material of this group. Dr. H. H. Rusby has 

 given valued information and supplied material of certain 



specimens collected by M 



gentlem 



the writer is under obligation and takes this opportunity to 

 express his personal gratitude. 



A critical study of this relatively large assemblage of spec- 

 imens of South American Senecios has made it possible to 

 identify many of the earlier species published by Kunth, De 

 Candolle, Weddell, and others, as well as many of the more 

 recent species described by Klatt, Hieronymus, and contempor- 

 ary authors. It has seemed advisable to record a partial list of 



3 identified and to present descriptions of t 



iear not to have been previously described 



aberrans Greenm.. so. nov. 



Herba 



Plate 3. 

 subarach- 



denique plus minusve glabrato 



folioso; foliis alternis petiolatis oblongo-lanceolatis 10-15 cm 



longis 2-4 cm. latis acuminatis acutis leviter sinuato-calloso- 

 serratis basi rotundatis vel cuneatis iuventate utrinque 



arach 



1 Issued September 28, 1923. 



( 73 ) 



