Floral bracts very small, shallowly infundibuliform, 
spreading, apiculate. Flowers small, apparently secund, 
strongly bilabiate, ringent. Sepals 3-nerved, tubular- 
concave, densely short-pubescent within. Dorsal sepal 
ovate, short-acuminate, rather fleshy, very shortly con- 
nate at base with the lateral sepals, about 4 mm. long 
and 2 mm. wide when expanded. Lateral sepals entirely 
connate into a suborbicular-ovate deeply concave lamina 
which is 6-nerved, bicarinate, about 3—-8.4 mm. long, 
and 8 mm. or more wide when expanded, thinner than 
the dorsal sepal. Petals much smaller than the sepals, 
concave, suborbicular when expanded, fleshy-thickened 
and broadly rounded above, 8-nerved, produced into a 
subapical blunt horn on the outer surface, about 0.6 mm. 
long and 0.75 mm. wide. Lip subequaling the petals, 
ovate-rhombic, sessile, obtuse, broadly cuneate at the 
base, apparently lightly trilobulate in the middle but 
entire when spread out, about 0.6 mm. long and 0.75 
mm. wide; dise with the entire central portion occupied 
by a very fleshy arched callus surrounding the concave 
apical part. Column minute, strongly dilated and tri- 
lobulate above. 
This species differs from the Ecuadorian Stelis nutans 
Lindl. in having conspicuous cauline sheaths, spreading 
floral bracts and a dissimilar lip. 
Cuzco: Prov. of Urubamba, between kil. 97 and 108, F.C.C., on 
rocks at 2200 meters altitude, flowers yellow, May 16, 1943, C. Vargas 
3413 (Typr in Herb. Ames No. 65211). 
Stelis triangulisepala C. Schweinfurth sp. nov. 
Herba parva, caespitosa, epiphytica. Rhizoma abbre- 
viatum. Caules filiformes, vaginis arcte tubulatis juven- 
tute obtecti. Folium unicum, erectum, inconspicue 
petiolatum; lamina anguste elliptico-oblonga vel oblan- 
ceolato-oblonga, subacuta, infra sensim angustata. Race- 
mi singuli vel plures,erecti vel diffusi, folium plusminusve 
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