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BOTANICAL EXPLORATION IN VENEZUELA - I 185
Pleurothallis humilis C. Schweinfurth, sp. nov.
Herba perparva, caespitosa, epiphytica. Caules secundarii abbreviati,
vaginis duabus imbricatis tubularibus obtecti. Folium
singulum, erectum, oblanceolatum vel lineari-oblanceolatum, apice
abrupte rotundatum, infra longe angustatum. Inflorescentiae filiformes,
singulae vel tres, saepissime folia superantes, supra univel
laxe triflorae. Flos parvus, tenuis. Sepalum dorsale valde
concavum, anguste lanceolatum, acuminatum. Sepala lateralia
similia sed angustiora, obliqua. Petala oblique linear!- lanceolata,
longe acuminaca, sepalis paulo breviora. Labellum multo minus, in
positu natural! oblanceolaco-oblongum, acutum, cum lobulis erectis
breviter rotundato-rriangulis in parte inferiore. Columna crassa.
Plant very small, epiphytic, caespitose. Roots fibrous, glabrous,
as stout as the stems. Stems abbreviated, about 8 mm. or less long,
entirely or very nearly enveloped by 2 tubular imbricating translucent
sheaths. Leaf solitary, erect, oblanceolate or linear-oblanceolate,
abruptly rounded above with a minutely tridenticulate tip, longnarrowed
below, fleshy-coriaceous and rich green with purple spots
in natural condition and revolute margins in the dried state, up to 18
mm. long and 3.5 mm. wide when expanded, the mid-nerve being sulcate
above and sharply carinate beneath in the dried specimen.
Inflorescences filiform, 1-3 near the summit of the stem, usually
more or less surpassing the leaf, 1- or loosely 3-flowered above.
Flower small but large for the plant, thin and translucent in the
dried specimen. Sepals and petals dull salmon-orange. Dorsal sepal
strongly concave, narrowly lanceolate, acuminate, 3-nerved, about
5 mm. long and 1.5 mm. wide when expanded. Lateral sepals similar
to the dorsal sepal, obliquely and narrowly lanceolate, acuminate,
shortly connate at the base, about 5 mm. long and 1 mm. wide.
Petals obliquely linear- lanceolate, long-acuminate, 1-nerved, slightly
shorter than the sepals, about 0.75 mm. side. Lip red, much
smaller than the other segments, oblanceolate-oblong in natural
position, acute, glabrous, with a pair of incurved triangular-rounded
lateral lobules near the basal third, about 2.25 mm. long and 0.5 mm.
wide above. Column stout, about 1.5 mm. long (Fig. 33).
Type in herb. Chi. Nat. Hist. Mus., no. 1203736, epiphyte on tree
on wooded slopes of Quebrada O-paru-ma, between Santa Teresita de
Kavanaye'n and Rib Pacairao (tributary of Rib Mouak), state of
Boh'var, alt. 1065-1220 m., November 20-21, 1944, Julian A. Steyermark
60383.
This little plant has several apparent allies. It differs from
Pleurothallis barbulata Lindl. in having much larger sepals and
petals and an eciliate lip. It has petals which are markedly unlike
those of P. pertenuis C. Schweinf. and P. sarcophylla Reichb. f.
Pleurothallis Steyermarkii C. Schweinfurth, sp. nov.
Herba terrestris, magna. Caules approximati, longi, apice unifoliati.
Folium ellipticum, apice abrupte acuminatum, infra longe an-