NEW OR NOTEWORTHY ORCHIDS 
arcuate, subequaling the petals, with a broad denticulate 
wing above, extended into a fleshy foot which runs nearly to 
the anterior margin of the lateral sepals. Ovary densely 
hispid. 
Pleurothallis sigmoidea is vegetatively similar to P. 
monsirabilis Ames, but the flowers do not suggest any close 
ally. The specific name is in allusion to the sigmoid lip. 
This species was described from many dried plants sup¬ 
plemented by fresh flowers preserved in alcohol. 
Costa Rica, Province of Guanacaste, Vicinity of Tila- 
ran, Paul C. Standley & Juvenal Valerio 46653, January 10- 
31, 1926. 500-650 meters altitude. (Type in Herb. Ames 
No. 33477); Standley & Valerio 44167; Standley & Valerio 
44181; Standley & Valerio 44215; Standley Sz Valerio 44554: 
Province of Guanacaste, El Arenal, Standley & Valerio 
45088, January 18-19, 1926. 485-600 meters altitude; ^^and- 
ky & Valerio 45095; Standley & Valerio 45141; Standley & 
Valerio 45205: Province of Guanacaste, Los Ayotes, near 
Tilaran, Standley & Valerio 45583, January 21, 1926. 600- 
700 meters altitude; Standley & Valerio 45599: Province of 
Guanacaste, Aguilares, Standley & Valerio 46350, January 
29, 1926. About 600 meters altitude. 
The collectors’ notes in the various numbers cite the 
facts that this plant grows on trees and that the flowers are 
pale green, pale yellow-green or yellowish, all with dark 
red or dark purple dots. 
Pleurothallis simplex A. 5. sp. nov. Herba epi- 
Phytica, caespitosa, mediocris. Caules monophylli, vaginis 
Paucis tubulatis laxis ornati. Folium ellipticum, crassum, 
valde obtusum. Inflorescentiae foliis multo longiores, singu- 
lae vel duae, subdense racemosae. Sepala ovata, in dorso 
earinata. Petala oblongo-oblanceolata. Labellum obovato- 
Pentangulum. 
Plant caespitose, up to 21.4 cm. tall. Roots fibrous, 
flexuous, glabrous. Stems monophyllous, 3-12.7 cm. long, 
adorned with 3-4 loose tubular sheaths of which the upper¬ 
most is largest and loosest. Leaf elliptic, 3.3-7 cm. long. 
37 
