3.
Epipremnum giganteum
(Roxb.) Schott
Epipremnum giganteum
(Roxb.) Schott, Bonplandia 5 (1857) 45; Prod. Syst. Aroid. (1860)
389; Engl. in DC., Monogr. Phanerogam. 2 (1879) 249; Engl. &
K. Krause in Engl., Pflanzenr. 37 (IV.23B) (1908) 59; Hook.f., Fl.
Brit. India 6 (1893) 548; Hemsley, Bot. Mag., 130 (1904) t. 7952;
Ridley, Fl. Mal. Penins. 5 (1925) 119 -- Pothos gigantea
Roxb., Fl. Ind. 1 (1820) 455 -- Monstera gigantea (Roxb.)
Schott, Wien. Zeit. Kunst, Literatur, Theater, Mode, 4th Quartal
(127) (1830) 1028 -- Scindapsus giganteus (Roxb.) Schott
in Schott & Endlicher, Melet. Bot. (1832) 21 -- Rhaphidophora
gigantea (Roxb.) Ridl., Mat. Fl. Mal. Pen. 3 (1907) -- Type:
Roxburgh Ic. 2117 (K).
Very large to gigantic root-climber to 60 m. Pre-adult plant forming
modest terrestrial colonies. Adult plant with stem 10--35 mm diam.,
internodes 1.5--20 cm long, separated by prominent leaf scars. Growing
stems smooth, glossy dark green, older stems sub-woody to exceptionally
corky, mid-brown. Robust foraging stems occasionally occurring.
Clasping roots sparse to rather prolific, feeding roots freely produced,
often reaching great length, minutely pubescent, later corky, mid-
to dark brown, growing tip pale yellow. Cataphylls and prophylls
soon drying and falling. Foliage leaves evenly distributed but lower
leaves often falling and then leaves tending to become clustered
distally. Petiole 33--62.5 cm x 6--20 mm, canaliculate, dark green
to slightly glaucous, smooth, air-drying pale brown; apical geniculum
20--25 x 5--12 mm, smooth, basal genuculum 2--4 cm x 7--15 mm, both
genicula greater in diameter than petiole, drying shrunken and deeply
sulcate, less than petiole diameter and almost black; petiolar sheath
extending to half way along the apical geniculum, at first sub-membranaceous,
soon drying scarious, later the margin breaking into regular sections
which eventually fall to leave a somewhat roughened edges. Lamina
5.5--120 x 8.5--50 cm, entire, oblong-elliptic, slightly falcate,
stiffly chartaceous to coriaceous, apex acute to slightly acuminate,
base unequal-rounded, one side often produced into a rounded to
truncate posterior lobe, glossy bright green, margins hyaline, prominently
reddish to yellowish in exposed situations; overall venation densly
striate, primary lateral veins simple, 10--15 (-22) per side, 1--1.5
cm distant, diverging from midrib at 70°--75°, often barely
or not differentiated from interprimary veins, interprimary veins
very numerous, prominent, remaining parallel to primary vein, all
higher order venation tesselate; midrib deeply impressed above,
very prominently raised beneath, primary venation raised on both
surfaces, noticeably so in dried material, higher order venation
obscure in fresh and scarcely visible in dried material. Inflorescence
solitary, rarely two or more together, first inflorescence subtended
by a fully to partially developed foliage leaf with a well developed
petiolar sheath. Peduncle 5--8 cm x 4--10 mm, stout, terete, bright
green. Spathe canoe-shaped, shortly but stoutly tapering, stiffly
coriaceous, gaping at anthesis, 16--33.5 x 5.5--16 cm when pressed
flat, exterior green, interior waxy-glaucous to deep yellow at anthesis,
air-drying mid-brown. Spadix 15.5--28.5 x 1.5--4.5 cm, sessile,
cylindrical, bluntly tapering towards the apex, orange at anthesis,
air-drying mid-brown. Flowers 2.5--4 mm diam. Stamens 4; filaments
1 x 0.5 mm; anthers narrowly ellipsoid 2 x 0.75--1 mm; ovary 3--10
x 2.5--4 mm, ellipsoid, basal part strongly compressed; ovules 2;
stylar region 4--10 x 1.5--4 mm, trapezoid, robust, apex flattened,
margins reflexed in dry material; stigma linear, 0.8--3 x 0.1--0.5
mm, longitudinal. Fruit light-green, reipening to dull orange, stylar
region greatly enlarged. Seeds slightly curved, c. 5 x 2 mm, glossy
pale brown.
Distribution
- Myanmar (?), Malaysia Peninsular, Singapore, Cambodia (?),Thailand,
Vietnam.
Habitat - Quartz
ridge vegetation, limestone and marble hills and cliffs, hill forest,
established oil palm plantation on iron-rich alluvium, damp lowland
rainforest, swamp forest. 90--170 m.
Notes - 1. Epipremnum
giganteum is one of the most readily recognizeable species by
virtue of the bright green coriaceous leaf lamina with prominent
dense striate venation. In exposed situations, for example the trunks
of oil palm, the leaf colour intensifies and is further enhanced
by the red or yellow tint taken on by the hyaline margin of the
lamina. Forest specimens tend towards legginess with
widely separated leaves and duller leaf laminae. Epipremnum giganteum
often remains in logged-over areas, forming a distinctive high-climber
on remaining once-emergent trees.
2. This is the only Epipremnum species that seems to flower
regularly on both adherant and free stems (even on the same plant,
Boyce & Hay independent pers. obs.). The newly opened inflorescences
have a strong smell of peanut butter (Boyce pers. obs.). Most collections
are of the glaucous-spathed plant but forms with a rich yellow spathe
interior are not rare.
3. Specimens of E. giganteum are not common in herbaria even
though it is one of the ubiquitous climbers in Peninsular Malaysia.
I suspect that field workers often simply pass it by because it
is so large.
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