REVISION OF THE SOUTH AMERICAN 
SPECIES OF CUSCUTA , 
I ' • 
T. G. YUNCKER 
(Received for publication March 25, 1922) 
In a recent study of the North American and West Indian species of 
Cuscuta^ the writer had the opportunity of examining a number of speci- 
mens from South America. It was apparent that the species occurring in 
the two continents were closely related, and it was thought that a careful 
study should also be made of those of South America. The present paper 
presents the results of a study of those species known to occur in South 
America and the Galapagos Islands. 
Ruiz and Pavon,^ in 1798, described two species of Cuscuta which seem 
to have been the first to be listed from South America. Humboldt, Bon- 
pland, and Kunth,^ in 18 18, described four species from the western coast. 
Choisy,^ in 1841, in his monograph included several species from different 
parts of the continent, while Gay,^ in 1849, listed five species as occurring 
in Chile. Engelmann,*^ in his monograph of the genus, described all the 
species then known and is the only writer who has given us anything like 
an adequate treatment of the group. Progel,^ in 1871, described the species 
for Brazil, and Reiche,^ in 1910, described eight species for Chile. 
Thirty-eight species are included in this paper, seven of which are 
believed to be new to science. In addition to these there are five new 
varietal segregations which have seemed necessary for an adequate under- 
standing of the species in which they occur. Of these thirty-eight species, 
eight are also found in North America or the West Indies, or in both. Only 
one species, Cuscuta epithymum Murr., belonging in the subgenus Succuta, 
which is typically an Old World group, has been seen from South America, 
and of this but one specimen. All the other species belong to the subgenus 
Grammica, which also includes all those of North America and the West 
Indies, with the exception of four introduced from Europe and of Cuscuta 
^ Yuncker. Illinois Biological Monographs 6: 95. 1921. 
2 Ruiz and Pavon. Fl. Peruv. et Chili, i: 69. 1798. 
2 Humboldt, Bonpland, and Kunth. Nov. gen. et spec. pi. 3: 121. 1818. 
^ Choisy. Mem. Soc. Phys. Hist. Nat. Geneve 9: 261. 1841. 
5 Gay. Histoire de Chile 4: 445. 1849. 
^ Engelmann. Trans. Acad. Sci. St. Louis i: 453. 1859. 
Progel, in Martins' "Flora Brasiliensis " 7: 372. 1871. 
^ Reiche. Flore de Chile 5: 166. 1910. 
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