TROPICAL AMERICAN ORCHIDS 
suborbiculare, apice trilobatum; lobis lateralibus semi- 
orbicularibus, sublobatis; lobo medio minore. 
Plant caespitose, 19 cm. tall. Roots numerous, fibrous, 
glabrous, very slender. Stems 3-8.5 cm. long, entirely con¬ 
cealed by three sheaths, monophyllous. Sheaths tubular, 
loose, membranaceous when dry. Leaf erect, oblong; lamina 
6.25-9 cm. long, 8-11 mm. wide, obtuse to broadly rounded 
at the apex, coriaceous, the mid-nerve conspicuously cari¬ 
nate beneath, cuneate-narrowed to a sulcate petiole about 
1 cm. long. Inflorescence solitary, about 12 cm. long, ar¬ 
cuate, subequaling the leaf, secund, densely many-flowered, 
especially above, base of the peduncle clasped by a rugose 
sheath 1.4 cm. long. Floral bracts infundibuliform, exceed¬ 
ing the ovary. Flowers minute, tubular-campanulate, as 
usual in the genus, about 2.4 mm. long. Sepals all connate 
for 1 mm. or less; free portion ovate-lanceolate, erect and 
parallel, 3-nerved. Petals very minute, lanceolate, obtuse, 
1-nerved, about .9 mm. long. Labellum suborbicular in out¬ 
line, about 1 mm. long, sharply 3-lobed at the apex; lateral 
lobes relatively large, semiorbicular, irregularly lobulate 
above the middle; middle lobe relatively small, triangular- 
ovate, broadly rounded at the tip. Disc 3-nerved, a pro¬ 
nounced transverse thickening with a posterior depression 
at the base. Column minute, provided with a broad dentate 
wing at the apex. 
There appears to be no near ally of this minute-flowered 
species. [Plate 22: habit X about 2. 1, flower, side view 
X 6. 2, dorsal sepal X 9. 3, column and labellum, side 
view X 12. 4, labellum X 18. 3, lateral sepals X 9. 6, 
column X 18. 7, petal X 12.] 
Panama, Province of Chiriqui, Caramillo, C. W. Powell 
345, October 1923. 5000 feet altitude. “Grows on fallen 
trees and stumps. Medium sunlight. Flowers pale greenish 
white.” (Type in Herb. Ames No. 27298.) 
Physosiphon obliquipetalus A. & S. sp. nov. Herba 
gracilis, caespitosa. Caulis vaginis inconspicuis arete or- 
natus, unifolius. Folium erectum, lanceolato-oblongum, 
coriaceum, crassum in vivo, medio acute sulcatum. Inflo- 
12 
