6-8 cm. wide, lateral veins four, in life glossy and bluish 
green above (straw-colored when dried), the surface very 
minutely tessellate under a glass, nerves not elevated, in 
life paler green beneath with all nerves prominently ele- 
vated, rather densely but minutely whitish tomentulose. 
Petiole robust, brownish black, mostly 2-8 cm. long. 
Racemes very short, congested, few-flowered, axillary. 
Flowers up to 8 cm. long with glabrous, slender pedun- 
cles up to 2 cm. long. Basal portion of perianth strongly 
ovoid-dilated, 18 mm. long, 10-11 mm. in diameter, 
glabrous or glabrescent, yellowish brown or pale purple 
without; tube obconic, purple-veined, straw-colored or 
yellow-brown, up to 8 cm. long, basally 4 mm. but api- 
cally 20 mm. in diameter, constricted into a small mouth, 
distantly papillose within; one lip expanded only on one 
side, truncate on the other, membranaceous, dark blood- 
red within, but outside, purple at the base and brownish 
green near the apex, oval, 42 mm. long, 20 mm. wide, 
ecaudate, apically with a slit up to 2 mm. deep, subcu- 
cullate in life, glabrous. Column 5 mm. long, apex 2.5 
mm. in diameter, short-stipitate, divided into six parts for 
half its length; the pseudo-styline lobes acute. Stamens 
six in asingle whorl, adnate to the column; the anthers 
linear, up to 2.2 mm. long, longitudinally dehiscent. 
Fruit unknown. 
Cotompia: Comisaria del Vaupés, Rio Negro, San Felipe (El Cas- 
tillo), below confluence of Rios Guainia and Casiquiare. “‘Vine. Leaves 
thick. Flowers brownish red outside, tip greenish brown outside. In 
caatinga.’’ December 12, 1947, Richard Evans Schultes & Francisco 
Lopez 9296. 
Aristolochia Amesiana does not appear to be closely 
related to any of the described species of this interesting 
genus. It is at once set off as distinct by the extremely 
thick-coriaceous texture of its leaves. In having leaves 
which are elliptic with a rounded (never even slightly 
[ 187 | 
