TROPICAL AMERICAN ORCHIDS 
British Guiana, Rockstone, dense upland forest, along 
the railroad track,//. A. Gleason 594, 673, and 738, July 15 
to August 1, 1921. (Herb. N. Y. Bot. Gard.) 
Vanilla latisegmenta A. & S. sp. nov. Herba scan- 
dens. Caulis in sicco striato-angulatus. Folia elliptico- 
ovata, acuminata, sessilia. Radix singula oppositifolia. In- 
florescentiae axillares, pauciflorae. Flores pro genere me- 
diocres. Sepala lanceolata, acuminata. Petala similia. La- 
bellum basi columnae breviter adnatum, leviter trilobatum, 
margine valde plicato. Discus lineis crassis internerviis atque 
lamella lata per medium ornatus. Columna gracilis, gla- 
berrima. 
Stem scandent, flexuous or arcuate, striate-angulate, 
smooth, 2.4 mm. in diameter, internodes 4-6.5 cm. long (a 
single terminal internode only 1 cm. long), opposite each leaf 
a short stout fibrous root which is longitudinally sulcate when 
dry. Leaves elliptic-ovate, about 13-20 cm. long, 6.3-8.7 
cm. wide, rather abruptly acuminate, sessile, many-nerved 
with cross reticulations, shining. Inflorescences axillary, 
short, about 5-flowered. Rachis stout, strongly fractiflex, 
4-5 cm. long. Floral bracts triangular-lanceolate, concave, 
amplexicaul, 1.5 cm. or less long. Flowers medium-sized for 
the genus. Pedicellate ovary of mature flowers 4-4.6 cm. 
long. Lateral sepals broadly lanceolate, 4.6-5.2 cm. long, 
1.75-2.1 cm. wide, narrowed to the acute apex which is very 
oblique, 13-nerved. Dorsal sepal similar, about 1.55 cm. or 
more wide below, sometimes thicker in texture through the 
longitudinal middle of the lower three-fourths, 11-nerved. 
Petals elliptic-lanceolate, lightly oblique, about 4.6-4.9 cm. 
long, 1.5-1.8 cm. wide, acute and very obliquely bilobed at 
the apex, thickened through the centre with a longitudinally 
central groove on the outer surface, 11-nerved. Labellum at 
base adnate to the column for about 6 mm., when expanded 
roughly hexagonal in outline, about 4.4 cm. long and as wide 
above the middle, free portion rounded below then flabel- 
late-dilated to a lightly 3-lobed apex with its anterior mar¬ 
gins strongly plicate, apex abruptly mucronate. Disc marked 
by a conspicuous broad central fleshy band which is some- 
2 
