Rhaphidophora korthalsii Schott

First published in Ann. Mus. Bot. Lugduno-Batavi 1: 129 (1863)
This species is accepted
The native range of this species is Arunachal Pradesh, S. Nansei-shoto, Peninsula Thailand to Malesia and W. Pacific. It is a climber and grows primarily in the wet tropical biome.

Descriptions

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

Habitat
Disturbed lowland primary or secondary dipterocarp forest, lower and upper hill forest, wet pre-montane and montane forest, on granite, sandstone, clay and limestone, occasionally in freshwater swamp forest.
Diagnostic
In Peninsular Malaysia confusion with Rhaphidophora tetrasperma and R. nicolsonii is possible. The former is readily separable by the generally smaller and comparatively broader adult leaves (to 42 x 38 cm), and by the individual pinnae lacking the prominent parallel primary lateral veins and in never being perforated close to the mid-rib. Rhaphidophora nicolsonii is distinguished by the ovate leaves and by the petiolar sheath extending 1/2 - 3/4 along the petiole. Fertile material of R. korthalsii and Epipremnum pinnatum is readily separated by the shape of the style apex (round versus trapezoid) and the shape and orientation of the stigma (± punctiform and circumferential versus strongly linear and longitudinal) and, if fruits are mature, by seed characters. The fruits of R. korthalsii each contain many small ellipsoid seeds with a brittle, smooth testa whereas E. pinnatum has fruits with two large, strongly curved seeds with a bony and ornamented testa.
General Description
Very large, occasionally enormous, slender to rather robust, pachycaul, heterophyllous liane to 20 m; seedling stage a non-skototropic shingling juvenile shoot; pre-adult plants never forming terrestrial colonies; adult shoot architecture comprised of greatly elongated, clinging, physiognomically monopodial, densely leafy, flowering stems; LEAVES: stems smooth, bright green, with sparse to copious prophyll, cataphyll and petiolar sheath fibre, especially at the stem apices, internodes to 15 x 3.5 cm, separated by prominent oblique leaf scars, older stems sub-woody; flagellate foraging stems absent; clasping roots densely arising from the nodes and internodes, prominently pubescent; feeding roots abundant, adherent and free, very robust, densely ramentose-scaly; leaves distichous; cataphylls and prophylls membranous, soon drying degrading to intricately reticulate fibres, these only very slowly falling; petiole shallowly grooved, upper part ± terete, (1 -) 9-65 x 0.2-1.5 cm, smooth, apical and basal genicula prominent; petiolar sheath prominent, membranous, strongly to slightly unequal on one side, extending almost to or reaching the apical geniculum, of ± short-duration, soon degrading into persistent netted fibres, these eventually falling to leave a prominent, slightly corky scar; lamina of seedlings overlapping in the manner of roof shingles, entire, lanceolate, 5-11 x 3.5-6 cm, base slightly cordate, lamina of pre-adult and adult plants free, entire, pinnatipartite, pinnatisect or pinnatifid, 10-44 x 14-94 cm, broadly oblong-elliptic to oblong lanceolate, slightly oblique, membranous to chartaceous or sub-coriaceous, base truncate and very briefly decurrent, apex acute to acuminate, individual pinnae 1-10 cm wide, frequently perforated basally adjacent to the mid-rib, thus appearing stilted; mid-rib very prominently raised abaxially, slightly sunken adaxially; primary venation pinnate, raised abaxially, somewhat impressed adaxially, 2-4 primary veins per pinna; interprimaries sub-parallel to primaries, slightly raised abaxially, slightly impressed adaxially; secondary venation strongly reticulate, slightly raised; tertiary venation invisible; INFLORESCENCE solitary to several together, first inflorescence subtended by a membranous prophyll and one or more cataphylls, these swiftly degrading to netted fibres, subsequent inflorescences subtended by one or more swiftly degrading cataphylls, the whole forming a mass of developing and open inflorescences and developing infructescences partially concealed by persistent netted cataphyll and prophyll remains; peduncle slightly laterally compressed to terete, 6-26 x 1-1.5 cm; spathe narrowly canoe-shaped, stoutly beaked, 10-30 x 3-5 cm, stiffly fleshy, greenish to dull yellow, gaping wide at female receptivity and then swiftly falling to leave a large straight scar at the base of the spadix; spadix cylindrical, sessile, inserted ± level on peduncle, 9-26 x 1.5-2 cm, dull green to dirty white; stylar region rather well developed, mostly rhombohexagonal, 1.5-2 x c.c. 2 mm, slightly conical; stigma punctiform to slightly elliptic, if the latter then mostly longitudinally orientated, c.c. 0.3-0.5 x 0.2-0.4 mm; anthers barely exserted at anthesis; INFRUCTESCENCE 14-27 x 3-3.5 cm, dark green ripening to dull orange, stylar tissue abscising to reveal orange ovary cavity pulp.
Distribution
Peninsular Malaysia (Kelantan, Pahang, Penang, Perak, Selangor, Terengganu), Singapore. Widespread throughout south tropical Asia from Sumatera and southern Thailand to Borneo and the Philippines eastwards through the tropical western Pacific.
[CATE]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0
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    • Haigh, A., Clark, B., Reynolds, L., Mayo, S.J., Croat, T.B., Lay, L., Boyce, P.C., Mora, M., Bogner, J., Sellaro, M., Wong, S.Y., Kostelac, C., Grayum, M.H., Keating, R.C., Ruckert, G., Naylor, M.F. and Hay, A., CATE Araceae, 17 Dec 2011.
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Science Photographs

    • Copyright applied to individual images