TROPICAL AMERICAN ORCHIDS 
sheath. Raceme short, dense, distichously many-flowered, 
usually less than 1 cm. long (rarely up to 1.8 cm. long). 
Floral bracts sheathing the slightly longer pedicels, exte¬ 
riorly cellular-pubescent, shallowly infundibuliform at base. 
Flower minute, membranaceous, about 5 mm. across from the 
tip of the dorsal sepal to the tips of the laterals. Lateral 
sepals lanceolate-ovate, connate for about one-third of their 
length, 3 mm. long, 2-nerved, cellular-ciliolate especially on 
the outer margins, the acute tips more or less recurved. Dor¬ 
sal sepal broadly ovate, 2.5 mm. long, sharply acute, 3-nerved, 
somewhat cellular-ciliolate on the margin. Petals lanceolate, 
almost dimidiate, with the anterior division abbreviated, 
about 1.9 mm. long, obtuse. Labellum 3-lobed; lateral lobes 
dolabriform, dilated at the apex into the transverse flat¬ 
tened lanceolate surfaces usual in the genus, about .5 mm. 
long, wider at the apex; middle lobe minute. Column char¬ 
acteristic of the genus, clinandrium abruptly mucronate at 
the summit. 
Lepanthes subdimidiata resembles L. Turialvae Reichb. f. 
in habit, but the almost dimidiate petals are distinctive. 
Costa Rica, Pejivalle, C. H. Lankester 839, May 29, 
1924. 3000 feet altitude. “Sepals hyaline pinkish, petals dull 
reddish purple marginally centrally dull orange, leaves deep 
velvet green, upper surface like shagreen.” (Type in Herb. 
Ames No. 28693.) 
Hexisea sigmoidea A. & S. sp. nov. Herba insignis. 
Caules ex internodiis gracilibus constant, in nodis ramosi. 
Folia bina in nodis, anguste oblonga. Flores singuli, in apice 
internodii summi. Sepala ovato-lanceolata. Petala angus- 
tiora. Labellum sigmoideum; basis anguste concava; deinde 
lamina latere utrinque auriculata, parte anteriore abrupte 
reflexa cuneata late truncata. Columna crassa, antice in 
medio tumefacta. 
Stems branching at the nodes; internodes successively 
shorter from base upward, .6 (uppermost)-21.3 (lowermost) 
cm. long (perhaps more), 2-2.5 mm. in diameter (the lower¬ 
most), smooth, terete, the upper one longitudinally sulcate 
m the dried specimen clothed at base with tubular sheaths or 
