Chartreuse yellow with rose-purple diffusion, September 14, 1936, 
Lozado 6130; on trees, Barranca de la Mina, southwest of Urupan, 
State of Michoacan, at 1300 meters altitude, longitude 101°58/ west, 
latitude 19°26/ north, lip and petals brown, sepals Chartreuse yellow 
with purplish infusion, April 20, 1933, Nagel 2249 (Type in Herb. 
Ames No, 51956). 
Pleurothallis involuta is allied to P. abjecta Ames trom 
which it may be distinguished by the lateral sepals being 
free nearly to the base, not merely retuse; by the differ- 
ently shaped petals; by the smaller flowers; and by the 
smaller elliptic-oval to oval epetiolate leaves, instead of 
oblanceolate-elliptic petiolate leaves. 
Both collections of this species were intimately asso- 
ciated with another small orchid, Jacquiniella leucome- 
lana (Reichb.f.) Schltr. 
This species appears to be caespitose when in its nat- 
ural dense clusters, but the individual primary stems are 
actually found to be repent when they are separated 
from the mass. 
Pleurothallis longispicata L.O. Williams sp. nov. 
Herbae parvae, caespitosae, epiphyticae, usque ad 4.5 
em. altae. Folia elliptica vel oblanceolata, obtusa, car- 
nosa. Inflorescentia pluritflora, quam folia longior. Sepa- 
lum dorsale oblongo-lanceolatum, acutum vel obtusum, 
carnosum, trinervium. Sepala lateralia connata, oblongo- 
ovalia, basi gibbosa, trinervia. Petala oblongo-elliptica, 
obtusa, uninervia. Labellum subhastatum vel trilobula- 
tum; lobi laterales parvi, obtusi; lobus medius oblongus, 
verrucosus, bicallosus. Columna generis. 
Small, caespitose, epiphytic herbs. Secondary stems 
2.5-4.5 em. long, slender, covered with one or two scar- 
ious, brown sheaths which are often verrucose toward 
the base. Leaves 2.5 em. long and 0.8-1.5 cm. broad, 
elliptic to oblanceolate, obtuse, fleshy, about as long as 
or longer or shorter than the secondary stems. Inflores- 
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