MULFORD EXPLORATION OF THE AMAZON VALLEY 



217 



small. Style stout, nearly equaling the perigone, the three re- 

 curved stigmas about 2 mm. long. 



''A vine, 10 meters long, in cultivated ground." The petioles 

 are more or less twisted, as though affording support to the 

 stem. 



Ivon, 800 feet, Martin Cardenas, February 19, 1922 {no. 

 2071). 



Species near B. cdulis, but peculiar in its well-developed 

 petioles. 



DiOSCOREACEAE 



DioscoREA OBLONGIFOLIA Rusbv, Bull. N. Y. Bot. Gard. 6: 492. 



(Specimen in fruit.) Glabrous, the stems slender, terete, 

 reddish. Petioles 2 cm. or more long, reddish, strongly chan- 

 neled above and slialloAvly 2-sulcate beneath. Blades 5 to 7 cm. 

 long, 2.5 to 5 cm. wide, ovate, abruptly very short-pointed and 

 acute, lightly cordate, 7-costate, the lowest pair of ribs very 

 short, the second pair terminating in the margin about midway, 

 the third pair meeting at the summit, all connected by numerous 

 crooked, slender secondaries, the venation prominent beneath. 

 Leaves pale-green, especially beneath, thickish and rigid. Only 

 the lowest branch of one panicle seen. Common peduncle 1 dm. 

 long, slender, reddish. Branch 3 dm. long, pendulous, the rachis 

 very slender, the branchlets 5 to 7 cm. long, somewhat distant, 

 peduncled, the peduncles lightly nodose. Fruits on very short, 

 thick recurved pedicels, about 2 cm. broad and 1 cm. long, sub- 

 truncate at both ends, the margin thickened, the ^^^ngs thin and 

 pale-brown, the veins very numerous, faint. 



In copses of the pampas about Lake Rogagua, 1,000 feet, 

 Martin Cardenas, November 4, 1921 {no. 1629). 



Dioscorea ferruginicaulis 



Ferruginous throughout, especially the stems, with exceed- 

 ingly short, dense, somewhat glistening hairs. Stems slender, 

 sulcate, of a bright, light rust-color. Petioles similar, very slen- 

 der, 5 to 7 cm. long, strongly sulcate, the blades 4 to 7 cm. long, 

 and about as wide, ovate, cordate, with broad shallow sinus, the 

 summit abruptly produced into a short, acute, twisted point; 

 entire, very thin, light-green, slightly ferruginous, pale beneath, 

 slenderly and sharply 11-costate, the lowest two ribs on each side 



