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GrEocrRAPHICAL DisrripvTioN OF THE SPECIES OF CUsctitA In NortTH AMERICA: 
By Axripa M. CunNINGHAM. 
In the Year Book of the Agricultural Department, published in 1894, C. 
Hart Merriam, Chief of the Division of Ornithology and Mammalogy, gives a 
revision of the work theretofore done in an endeavor to divide the country into 
distinct zones according to the plant and animal life found therein. And, since 
the distribution of all life depends so completely upon rainfall and temperature, 
these have been made the principal guides in locating the lines separating these 
zones, taking into consideration both latitude and elevation. He has divided 
North America into five zones as follows: Boreal, Transition, Upper Austral, 
Lower Austral, and Tropical. 
In the course of the study for the purpose of making a revision of the genus 
Cuscuta it was found of interest to note the geographical distribution of the genus 
in accordance with the plan adopted by Mr. Merriam. So far as the work has 
progressed, the material examined has been that contained in the herbaria of 
Harvard University, the botanical gardens of St. Louis, Missouri, and Purdue 
University, in all about 450 specimens. Among them, according to the nomen- 
clature heretofore adopted and still in use, we find thirty-two species and seventeen 
varieties, which are distributed throughout the five zones in the manner given 
below. But there is found here the same difficulty that has confronted us on 
diflerent occasions before, i. e., that the forms are so badly confused at present that 
any arrangement which might be made now is almost sure to need revision after 
a critical study of the genus. According to the present nomenclature, the distri- 
bution is as follows: 
Potosina, Palmeri, Americana, corymbosa, tinctoria, Jalapensis, mitreformis, flori- 
bunda and gracillima are confined-to the tropical zone and constitute the greatest 
number found in any one zone. 
The next greatest number found in only one zone is in the Transition. They 
are Epithymum, denticulata, rostrata and epilinum. 
Californica and subinclusa are found in the Tropical and Transition. 
Leptantha and chlorocarpa in the Upper Austral and Transition. 
Applanata and inflera in the Upper Austral. 
Cuspidata, compacta, decora, Gronovii and arvensis are distributed over the 
Upper Austral, Lower Austral and Transition. 
Squamata and odontolepsis in the Tropical and Upper Austral. 
Tenuiflora is found in three zones, i. e., the Transition, Upper Austral and 
Boreal. 
