TROPICAL AMERICAN ORCHIDS 
Plant caespitose, about 27 cm. tall, the stems strongly 
arcuate (in our specimen). Roots numerous, fibrous, flex- 
uous, glabrous, longitudinally sulcate when dry. Stems en¬ 
tirely invested by sheaths, leafless below, slender near the 
base and apex, apparently enlarged in the middle, 2-5 mm. 
in diameter in the dried state. Leaves about six, lanceolate 
or oblong-lanceolate, 7.5-11 cm. long, 1.35-1.85 cm. wide 
(the lower leaves much smaller), distichous, 2-2.8 cm. apart, 
the uppermost internode much shorter, long-acuminate 
above, cuneate-narrowed below, rather membranaceous, 
many-nerved with seven prominent nerves on the under 
surface. Inflorescence shorter than the leaves, racemose, 
arcuate. Peduncle below the raceme 5.1 cm. long, provided 
with tree sheaths. Sheaths narrowly lanceolate, membra¬ 
naceous, conduplicate in the dried specimen, the lowest 2.85 
cm. long, the upper ones shorter. Raceme 3.5 cm. long (per¬ 
haps longer in anthesis), densely flowered. Floral bracts 
lanceolate, membranaceous. Flowers small for the section. 
Sepals and petals apparently strongly reflexed in anthesis. 
Lateral sepals oblong-oblanceolate, 8.6-9 mm. long, 2.8 mm. 
wide above the middle when expanded, concave or navicular, 
acute, the apex thickened, three prominent nerves and a 
lesser nerve on each side; a conspicuous median keel ex¬ 
tends from the base to beyond the apex where it becomes 
more prominent. Dorsal sepal very narrowly elliptic, about 
9 mm. long, abont 2 mm. wide, navicular, acute, apex thick¬ 
ened, 3-nerved, with an inconspicuous nerve on each side 
toward the base, on the outer surface keeled toward the 
apex. Petals filiform, 8.7 mm. long, 1-nerved. Labellnm 
adnate to the tip of the column; lamina deeply 3-lobed, with 
the lateral lobes folded into reduplicate halves, about 4.5 mm. 
long, about 6 mm. wide between the apices of the terminal 
lobules when they are expanded; lateral lobes transversely 
oblong or shallowly dolabriform, the lateral margins irregu¬ 
lar, the free tips triangular falcate; middle lobe narrow, 
transversely spreading into divaricate linear-lanceolate 
obtuse lobules, with a broad blunt apicule in the shallow 
sinus. Disc with two fleshy calli at the base and three long 
approximate fleshy calli extending from the basal calli to the 
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