558 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9, 
exaltata Engelm., belonging in the subgenus Monogyna. The majority of 
the species belong in the section Eugrammica which is characterized by 
having a circumscissile capsule. None, however, possess capsules with as 
definite a line of circumscission as do some of the Mexican or Old World 
species, and a few which I consider as circumscissile have capsules that do 
not open easily until fully ripened. Some are found infesting trees, a 
characteristic exhibited by one or two Mexican species. Most, however, 
prefer herbaceous hosts. 
Many points doubtful to Engelmann because of poor and inadequate 
specimens have been explained, it is believed, through the examination of 
more abundant materials. Several species have been moved out of the 
section in which Engelmann placed them into others because of this fact. 
Excepting those species that also occur in North America or the West 
Indies, and which are illustrated in the paper^ on those species, all are 
pictured, many of them, it is believed, for the first time. The sketches were 
all drawn to scale with the aid of an Abbe camera lucida. References to 
the principal papers and illustrations are given for each species. 
During the progress of the study the writer had the privilege of exam- 
ining a number of collections and was greatly aided by the courtesy shown 
him by the persons in charge of those collections. In all cases he was 
granted every consideration for the furtherance of the work and desires to 
take this opportunity of expressing his appreciation. Some of the collec- 
tions were loaned for detailed study, and in other instances fragments of 
the specimens were generously supplied. The most valuable collection in 
this country is the Engelmann herbarium at the Missouri Botanical Garden, 
which includes Engelmann's types. In addition to this, the other collections 
studied are those belonging to the following institutions and individuals: 
Dr. Otto Buchtien, La Paz, Bolivia; Institute at Butantan, Brazil; Botanic 
Institute, Dahlem; Field Museum; Boissier Herbarium and the general 
herbarium of the Botanic Institute of the University of Geneva; Gray 
Herbarium; Royal Botanic Garden at Kew; New York Botanical Garden; 
Museum of Natural History, Trinidad, Paraguay; Museum of Natural 
History, Paris; Imperial Museum, Stockholm; United States National 
Herbarium; Botanical Museum, Utrecht; University of Zurich. In addi- 
tion to these, I wish also to thank Professor and Mrs. E. W. D. Holway of 
the University of Minnesota and Dr. Ivar Holmgren of the Botanical 
Institute of the University of Stockholm, who collected and sent to the 
writer many excellent specimens of Cuscuta while on journeys in South 
America. 
Systematic Arrangement of the Species 
For the descriptions of the genus, subgenera, sections, and subsections, 
together with the synonymy for each, see Yuncker, 111. Biol. Monogr. 6: no 
et seq. 1921. 
^ Yuncker, I.e. 
