A NEW ARISTOLOCHIA FROM 
AMAZONIAN COLOMBIA 
BY 
Ricuarp Evans ScCHULTES' 
The caatingas of the upper Rio Negro area of Brazil, 
Colombia and Venezuela are fascinating to the naturalist 
because of the curious adaptation of their flora to xero- 
phytism and because of the extraordinary number of en- 
demics and primitive species which they harbor. 
It was Spruce who, a century ago, first investigated 
these formations. Notwithstanding the thoroughness of 
Spruce’s work and the collections of a number of later 
botanists, the composition and history of the caatinga- 
flora is but little understood. Every expedition into the 
upper Rio Negro basin brings back novelties and rare 
plants. Some of these indicate phytogeographical rela- 
tionships with the flora of the great Venezuelan-Guianan 
land-mass; others, like the new concept which is de- 
scribed below, appear to stand alone with no close allies 
amongst the known species of South America. 
Aristolochia Amesiana RP. HL. Schultes sp. nov. 
Frutex scandens, robustissimus. Caulis volubilis, elon- 
gatus, paulo ramosus; rami volubiles, teretes, striolati, 
'Botanist, Division of Rubber Plant Investigations, Bureau of Plant 
Industry, Soils, and Agricultural Engineering, Agricultural Research 
Administration, U. S. Department of Agriculture; Research Fellow, 
Botanical Museum of Harvard University. 
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