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188 FIELDIANA: BOTANY, VOLUME 28
Pleurothallis sub til is C. Schweinfurth, sp. nov.
Herba mediocris, epiphytica. Rhizoma abbreviatum. Caules
secundarii approximati, graciles, a basi decumbent! suberecti, apice
unifoliati. Folium lineare, apice abrupte tridentatum, basi cordatum,
coriaceura, marginibus revolutis. Inflorescentiae azillares, uniflorae,
singulae vel plures. Flores perparvi, flavidi, glabri. Sepalum
dorsale valde concavum, suborbiculari-ovatum, obtusum. Sepala
lateralia in laminam concavam suborbicularem, apice bidentacam
connata. Petala falcata, oblongo-lanceolata. Labellum ovatum,
obtusum, valde incrassatum, basi abrupte reflezum et a latere visum
sigmoideum. Columna valde arcuata, supra dilatata.
Plant medium-sized, epiphytic, apparently caespitose. Roots
fibrous, filiform, glabrous, numerous. Secondary stems very variable
in size, numerous, slender, rigid, suberect from a decumbent base,
1-leaved at the apex, enveloped below by one to three close tubular
evanescent sheaths, up to 19 cm. long. Leaf commonly horizontally
spreading or reflexed, linear, narrowed above to an abrupt minutely
tridentate apex of which the middle tooth is produced into a conspicuous
mucro, cordate at the base, coriaceous with strongly revolute
margins, very variable in size, up to 12.7 cm. long and about 8
mm. wide when expanded. Inflorescences axillary, abbreviated, 1-
flowered, solitary or several (up to 7), enclosed by an evanescent
concave spathe. Flower very small, bilabiate, glabrous, with sepals,
petals and column pale yellow and lip deep yellow. Sepals concave.
Dorsal sepal suborbicular-ovate, obtuse, 3-nerved, about 3.5 mm.
long and 2.5 mm. wide when forcibly expanded. Lateral sepals
connate into a suborbicular lamina which is bidentate at the apex,
4-nerved, and slightly shorter but broader than the dorsal sepal.
Petals falcate, oblong-lanceolate, obtuse, 1-nerved, with slightly
irregular margins, about 3*3 mm. long and 1 mm. wide. Lip ovate,
very fleshy, obtuse, abruptly reflexed at the base and sigmoid in
natural position when viewed from the side, cordate at the base when
viewed from the front, about 2 mm. long and 1.5 mm. wide. Column
strongly arcuate, abruptly dilated above (Fig. 35).
Type in herb. Chi. Nat. Hist. Mus., no. 1206354, isotype in Herb.
Ames no. 64845, rich forest on slopes near summit of Cerro San Isidro,
above La Carbonera, state of Merfda, alt. 2430-2475 m., April 22,
1944, Julian A. Steyermark 56030, "epiphyte on Ladenbergia undata,
leaves dull blue green above and paler beneath".
This species differs from the Bolivian Pleurothallis scleropus
Schltr. in having smaller flowers with dissimilar sepals. It is ^egetatively
similar to the narrow-leaved form of the Peruvian P. juninensis
Schltr.
Octomeria rhizomatosa C. Schweinfurth, sp. nov.
Herba epiphytica, pro genere alta et rigida. Rhizoma repens,
elongatum ut videtur. Caules secundarii graciles, apice unifoliati,