12. Pothos lancifolius
Hook.f..
Pothos lancifolius Hook.f.,
Fl. Brit. Ind. 6 (1893) 554; Engl. in Engl., Pflanzenr. 21 (IV.23B)
(1905) 40. Type: Malaysia, Perak (probably Bk Larut), Scortechini
576 (fl.) (K! holo; SING! iso). Pothos penicilligerGagnep.,
Notul. Syst. 9 (1941) 135, syn. nov. Type: Vietnam, Col des
Nuages, near Tourane (modern Danang), Poilane 8089 (fl.) (P! holo;
GH!, SAI! iso),
Moderate, slender to somewhat robust heterophyllous root-climbing
liane to 4 m. Eocaul not observed; stem of juvenile shoot to 3 mm
diam., terete in cross section, shingle-leaved; stem of mature sterile
shoot to 6 mm diam., terete in cross section, mid-green, becoming
brown with age, densely clothed with leaves, but stems eventually
becoming naked, naked portions with prominent, 50 80 mm distant
nodes, often producing long, adherent feeding roots, these strongly
flattened with a prominently warty epidermis; stem of fertile shoot
to 4 mm diam., terete in cross section, densely clothed with leaves.
Leaves when fresh mid-green adaxially, slightly paler abaxially, stiffly
chartaceous, air drying dull greenish brown, midrib paler, prominently
raised; petiole 40 140 x 1.5 2 mm, slender, sheath rather
prominent, extending to just below geniculum, basally clasping, apically
briefly ligulate; lamina 100 250 x 25 100 mm, ovate
to elliptic or narrowly lanceolate, with 2 intramarginal veins per
side, the lowermost arising from the base, the next arising from the
lower part of the midrib, outer intramarginal vein remaining very
close and parallel to margin, inner vein c.5 mm distant, both reaching
the leaf tip, base rounded, apex long-attenuate, attenuate or acute,
minutely tubulate. Flowering shoot abbreviated, leafy, arising from
most of the mid- to distal leaf axils of fertile shoots. Inflorescence
solitary, occasionally paired; peduncle, 15 50 x 1.5
3 mm, stout, spreading, dull greenish yellow; spathe 25 100
x 10 40 mm, lanceolate, slightly cucullate, base barely decurrent
on the peduncle, apex acuminate, green to purplish-green, slightly
softly-leathery; spadix sessile, 15 50 x 3 9 mm, cylindrical,
dark to yellow-green. Flowers c. 1.5 mm diam.; tepals 1 x 0.3 mm,
oblong-cymbiform, green, apex slightly fornicate, triangular, truncate;
stamens 1 4 x c. 0.5 mm, filaments strap-shaped, thecae c.
0.2 mm diam, creamy-yellow; ovary 1 1.5 x 0.25 0.75
mm, compressed angular-ellipsoid, green; stylar region turbinate;
stigma disc-like, prominent. Infructescence with numerous berries,
mostly born towards the bottom of the spadix; fruit 10 15 x
10 11 mm, ellipsoid-bottle-shaped, ripening deep scarlet, with
prominent basal leathery and chartaceous tepal remains and a large
stigmatic remnant. Seeds c. 4 6 x 2 3 mm diam., ellipsoid.
Distribution Peninsular Malaysia, Vietnam.
Habitat & Ecology Degraded dry to damp seasonal
evergreen hill forest on clay soils over granite. 750 1300
m.
Notes The type of P. penicilliger is an exceptionally
robust specimen of P. lancifolius, a species hitherto
considered to be restricted to Peninsular Malaysia. Despite the dimensions
of the type, other Vietnamese collections of P. penicilliger
seen match very well typical P. lancifolius. I have
no hesitation is assigning P. penicilliger to Hookers earlier
name.
Pothos lancifolius is morphologically most similar to P.
kingii. It may be distinguished from P.
kingii by the lanceolate, not cucullate, spathe and the bottle-shaped
fruits with large, broad, stigmatic remains. Confusion may occur with
the seldom-collected P. touranensis
from which fertile P. lancifolius is distinguishable
by the smaller inflorescences carried on much shorter peduncles; see
P. touranesis for further discussion of this character. Confusion
is also possible with P. lorispathus,
from which P. lancifolius may be separated by the lanceolate
(versus lorate) spathe, the sessile spadix and the bottle-shaped (versus
ovoid, obtuse) fruits.
Geographically representative selection of collections studied:
VIETNAM. Gia Lai: K'Bang, Son Lang, 17 June1988, Vu Xuan Phuong 1190
(fl.) (HN). Quang Nam Da Nang: Col des Nuages, 18 Sept. 1923,
Poilane 8089 (fl.) (type of Pothos penicilliger , P holo, GH,
MO, SAI iso). |