TROPICAL AMERICAN ORCHIDS 
Petals slightly larger than the sepals, elliptic to suborbicular, 
acute, 4.1-5 mm. long, 2.4-3.2 mm. wide, 3-nerved. Label- 
lum quadrate in outline, 7.1-8.1 mm. long, 4.9-6.4 mm. wide 
across the middle, deeply bilobed at the apex; lamina 
rounded at base, more or less rhombic-dilated in the middle, 
then narrowed and more or less dilated into two anterior 
subquadrate lobes; basal callus conspicuous, oblong to 
ovate-oblong, margin raised and finely papillose, depressed 
within and provided in the centre with a rounded boss. 
Column short and stout, with a pair of spreading rounded- 
triangular wings, adherent to the basal part of the 
lamina of the labellum. Pollinia pyriform, somewhat com- 
planate. 
One flower from the type specimen, in addition to being 
markedly smaller, has the sides of the lip not so sharply 
dilated and narrowed. A second collection {Powell 361) is 
a much narrower leaved plant, the leaves all less than 3 cm. 
long and 2.6-4 mm. wide near the base. A vegetatively inter¬ 
mediate caespitose plant {Powell 372) has a very slightly 
indented labellum and indistinct (possibly incomplete) 
column-wings. A caespitose plant {R. S. Williams 1008) 
reaching 19 cm. in height is apparently the same species, but 
it has no flowers. 
Lockhartia variabilis is a very variable species allied to 
L. Pitlieri Schltr., from which it differs in the lip, which is 
relatively much longer than the sepals and petals. It is 
separable from L. parthenoglossa Reichb. f. by its narrower 
sepals, its elliptic petals, and rounded column-wings, as well 
as by its narrower leaves. 
Panama, Wooded hills near Frijoles, C. W. Powell 355, 
January-February 1924. Sea level. Grows in medium shade. 
Flowers yellow with an orange boss at base of lip. (Type in 
Herb. Ames No. 28131.): Cativa-Porto Bello Trail, C. W. 
Powell 361: Ft. Sherman and mouth of Chagres River Trail, 
C. W. Powell 372, January 1924. “Found growing on mossy 
limbs in medium sun.”: Marraganti and Vicinity, R. S. 
Williams 1008, April 3-9, 1908. 10-200 feet altitude. “FIs. 
yellow, lip with red centre.” 
82 
