(Tyree in Herb. Field Mus. No. 534901; Dupticare tyre in Herb. 
Ames No. 60980); Tambo de Vaca, at about 3900 meters altitude, 
on trees, flowers greenish white, June 10-24, 1923, Machride 4344, 
4461a. (No. 4344 is a somewhat smaller plant vegetatively than the 
type and has shorter perianth segments); Alturas del Chaco, Santa 
Ana Valley, September 1928, Herrera 2124a (C. Bues coll.). 
Pleurothallis caudatipetala C. Schweinfurth sp. 
nov. 
Herba minuta, caespitosa, epiphytica. Radices cras- 
sae. Caules abbreviati, vaginis duabus celati. Folia obo- 
vata vel cuneato-spathulata, apice rotundata, marginata. 
Inflorescentiae unicae, saepe foliis breviores, uniflorae vel 
pauciflorae, floribus subumbellatis. Flores membranacel. 
Sepalum dorsale oblongo-lanceolatum, acutum, sparse 
longe ciliatum. Sepala lateralia in laminam elliptico- 
ovatam bidentatam connata, sparse longe ciliata. Petala 
a parte basali obovato-oblonga abrupte longe caudata. 
Labellum pandurato-oblongum, apice leviter retuso, 
marginibus maxima pro parte longe fimbriatis. Columna 
late alata. 
Plant minute, epiphytic, caespitose, up to 1.5 ecm. 
high. Roots fibrous, relatively stout, glabrous. Stems 
abbreviated, congested, monophyllous, invested by two 
tubular evanescent sheaths, up to 4mm. long. Leaf obo- 
vate to cuneate-spatulate, up to 11 mm. long and 4mm. 
wide, rounded or obtuse above with a median apicule, 
cuneate below, marginate, coriaceous. Inflorescences sol- 
itary, shorter than or subequaling the leaf, 1-flowered 
or fasciculately several-flowered. Flower small but large 
for the plant, membranaceous. Dorsal sepal oblong- 
lanceolate, acute, concave near the base, about 3.6 mm. 
long and 1.6 mm. wide, 3-nerved, sparingly long-ciliate. 
Lateral sepals connate into an elliptic-ovate lamina which 
is about 3.8 mm. long, sharply bidentate, obscurely 4- 
nerved, hirsute within and sparingly long-ciliate. Petals 
[175 ] 
