CENTRAL AMERICAN ORCHIDS 
formantia, lamina subtus bicarinata. Sepalum dorsale 
anguste ellipticum, obtusum, prope basim valde concavum, 
subtus per medium valde unicarinatum, supra pilis longius- 
culis purpureis appressis adspersum. Petala amethystina, 
columnam aequantia, oblonga, glabra, abrupte acuta, car- 
nosa. Labellum amethystinum, inaequaliter trilobatum; 
lobis lateralibus erectis, porrectis, oblongis, obtusis, basi 
truncatis; lobo medio permagno, oblongo, apice obtuse 
rotundato, glabro. Discus supra basim lobi terminalis 
bicarinatus, carinis valde incrassatis, prope unguem brevem 
bicallosus. Columna leviter arcuata, androclinio minute 
denticulate. 
Secondary stems 1-1.5 cm. long, slender, concealed by a 
tubular closely oppressed sheath, monophyllous. Leaf 
6-9 cm. long, 5-12 mm. wide. Peduncle with the raceme 
6-15 cm. long, with the flowers about 5 mm. apart. Floral 
bracts up to 3 mm. long. Pedicel with the ovary up to 
5 mm. long. Lateral sepals 8 mm. long, united to form a 
narrowly elliptical lamina which is bidentate at the tip, 
villose on the upper surface, more densely so near the 
margin than in the centre; when spread out the lamina 
is about 3 mm. wide. Petals 3 mm. long, 2 mm. wide. 
Labellum with the short claw 4 mm. long; lateral lobes 
basal, 2 mm. long, .75 mm. wide; middle lobe 3 mm. long, 
about 1.5 mm. wide. Column about 3 mm. long, at base 
produced into a short foot. 
Closely allied to Pleurothallis Wercklei Schltr., P. 
canae Ames, P. Johannis Schltr., P. bifalcis Schltr. and 
several other species of the Central American orchid flora. 
From P. Wercklei, with which it has been confused, it differs 
conspicuously in having the lateral lobes of the labellum 
much broader in relation to their length, in the truncate 
base of the lip forming with the claw a right angle on each 
side, and in the tip of the petals being abruptly acute, not 
triangular acute and obscurely trilobed when spread out. 
Guatemala, Department of Alta Verapaz, Samac, 
Harry Johnson 878, October 20, 1920. Flowers purplish. 
4000 feet altitude. (Type in Herb. Ames No. 21282.); 
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