e-Flora of Thailand

Volume 11 > Part 2 > Year 2012 > Page 277 > Araceae > Rhaphidophora

11. Rhaphidophora megaphylla H.Li

Acta Phytotax. Sin. 15(2): 102. 1977; V.D. Nguyen. Araceae. Checkl. Plant. Sp. Vietn. 3: 892. 2005; Li & Boyce in H.Li. et al., Fl. China 23: 112. 2010.


Accepted Name : This is currently accepted.


Description : Very large to gigantic, very robust, pachycaul, homeophyllous secondary hemiepiphyte climbing 40 m or more. Stems terete, on flowering shoots 3–4 cm diam., non-flowering shoots somewhat more slender. Leaves dense, spiro-distichous; petiole canaliculate, 50–70 cm; petiolar sheath extending to about half way along petiole, soon marcescent; leaf blade ovate-oblong, 50–90 by 28–50 cm, apex abrupt acuminate, base cordate, very stiffly leathery; primary lateral veins 10–13 each side, diverging at 80°–90° from midrib; interprimary veins much less prominent, striate; secondary and tertiary venation forming a conspicuous reticulum in dry material. Inflorescences in fascicles of up to four per synflorescence on the tips of primary clinging shoots, as synflorescence develops primary axis reiterating, overtopping the synflorescence such that the inflorescence cluster is displaced and appears to be produced laterally; peduncle green, 15–18 by ca 2 cm; spathe oblong-cymbiform, 20–27 by ca 16 cm, very thick, initially gaping, then spreading, greenish white, then light yellow, opening deep yellow internally; spadix cylindrical, 18–25 by ca 2.5 cm, sessile, yellow-green at anthesis, apex obtuse, base oblique; stigma pronounced-punctiform. Infructescence stoutly cylindrical, up to 30 by 5 cm, stylar tissue markedly blue-grey glaucous.


Thailand : NORTHERN: Chiang Mai, Lampang, Phitsanulok; SOUTH-WESTERN: Kanchanaburi.


Distribution : SW China (type), N Laos, N Vietnam.


Ecology : Evergreen forests or mixed deciduous lowland to montane forests, on granite and limestone; 680–1,000 m alt.


Notes: A very distinctive climber by virtue of its massive size. Remarkably, there are two such massive entire-leaved hemiepiphytic aroids in N Thailand, the other being Scindapsus maclurei (q.v.) from which Rhaphidophora megaphylla is readily distinguished by the punctate raised stigma (vs longitudinally elongated and flush) and in having the primary lateral veins much more prominent than the interprimaries (vs all veins of similar prominence).


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