TROPICAL AMERICAN ORCHIDS 
Pleurothallis acrisepala A. & S. sp. nov. Herba 
parva. Caulis minutus, unifolius. Folium oblanceolatum, 
apice minute tridenticulatum, interne sensim longe angus- 
tatum. Pedunculus quam folium longior, filiformis. Pedi- 
celli fasciculi, ex axillis bractearum orientes. Sepala lateralia 
in laminam ovato-lanceolatam connata. Sepalum dorsale 
oblongo-lanceolatum. Petala multo minora, obliquissime 
Iriangulari-spathulata. Labellum oblongo-lanceolatum, 
utrinque minute retrorso-lobulatum. 
Plant small, allied to P. Brighamii S. Wats. Roots 
fibrous, flexuous, glabrous. Stem minute, monophyllous, 
surrounded by fibres of sheaths. Leaf oblanceolate, 5.1-6.9 
cm. long, 9.5-12 mm. wide above the middle, acutish or 
rounded with a minutely bilobed and apiculate tip, very 
gradually narrowed toward the base to an indistinct slender 
channelled petiole, spreading, coriaceous in the formalin 
material, with the mid-nerve prominently sulcate above and 
carinate beneath. Peduncle below the inflorescence about 
8.5-9.55 cm. long, filiform, glabrous, with three remote 
tightly clasping tubular sheaths. Pedicels two to three, 
springing from the axils of closely imbricating infundibuli- 
form sheaths which are at the summit of the peduncle. 
Flowers one at a time, apparently purplish. Sepals very 
shortly connate into a shallow cup at the base but with 
spreading upper portions. Lateral sepals connate into an 
ovate-lanceolate lamina 8.15-9.1 mm. long (inclusive of the 
portion adnate to the column-foot), about 4 mm. wide, 
sharply bidentate for about one-third of their length, with 
narrow acuminate teeth, bicarinate on the outer surface, 
6-nerved. Dorsal sepal oblong-lanceolate, 8.5-9 mm. long, 
about 2.2 mm. wide, shortly but sharply acuminate, 
3-nerved, unicarinate on the lower half of the outer side. 
Petals much smaller than the sepals, about 3.5 mm. long, 
very obliquely spatulate, the forward margin round-dilated 
in the middle then narrowed to an acuminate thickened tip, 
the posterior margin straight, 2-nerved. Labellum oblong- 
lanceolate, 4 mm. long, about 1.2 mm. wide where broadest; 
claw minutely auricled on each side at the base. Disc re- 
trorsely hastate-auricled on each side below the middle and 
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