Rhaphidophora elmeri (Araceae)
Moderately robust, semipachycaul homeophyllous liane to unknown ultimate height; seedling stage not observed; pre-adult plants forming small terrestrial colonies; LEAVES: adult shoot architecture comprised of elongated, clinging, physiognomically monopodial, leafy, non-flowering stems and shorter, clinging, sympodial, densely leafy, flowering stems; stems smooth, slightly compressed-terete in cross-section, without cataphyll remains at the apices of active shoots, internodes to 2-8 x 1cm on free shoots, up to 2.5 cm on adherent shoots, separated by large slightly oblique leaf scars; flagellate foraging stems not observed; clasping roots densely arising from the nodes and internodes of stems, pubescent; feeding roots not observed; leaves distichous; cataphylls and prophylls large and conspicuous, membranous, quickly drying and falling; petiole channelled adaxially, slightly carinate abaxially, 13-25 x 0.4-0.7 cm, smooth, apical and basal genicula well defined; petiolar sheath very prominent, extending to and surrounding the apical geniculum, swiftly drying and soon falling ± whole to leave a conspicuous scar extending around the apical geniculum; lamina entire, oblong to oblong-lanceolate to lanceolate, slightly to rather markedly oblique, 16-34 x 8-14 cm, thinly coriaceous, base rounded to sub-truncate and very slightly decurrent, apex rounded-acuminate to acuminate with a slight apiculate tubule; midrib wide, prominently raised abaxially, especially proximally, slightly sunken adaxially; primary venation pinnate, slightly raised abaxially, densely pinnate and raised adaxially; interprimaries parallel to primaries and much less prominent abaxially, about as prominent as primary laterals adaxially, slightly raised abaxially and adaxially; secondary venation ± obscure in fresh material, visible as a very faint weak reticulum in dried specimens; INFLORESCENCE solitary, subtended by a large briefly persistent cataphyll; peduncle often very stout, compressed-cylindric, 13-22 x 0.7-2 cm; spathe not observed in entirety, seemingly persistent into fruiting and then rotting away at infructescence maturity; spadix stoutly tapering-cylindrical, often markedly curved, sessile, inserted strongly-obliquely on peduncle, 14-17 x 1-2.5 cm; stylar region rhombohexagonal, 0.9-1.2 x 1-1.1 mm, truncate; stigma cylindrical, raised, c. 0.15 mm diam.; anthers exserted at anthesis; INFRUCTESCENCE 16 x 2.5 cm.
Primary lateral veins on the abaxial leaf surface significantly more visible than interprimaries and never less than 5 mm apart. Spathe persistent during fruit development, eventually rotting away. Spadix 14-17 cm long Confusion with R. philippinensis is possible, although R. elmeri differs by flowering on clinging stems, in the proportionally narrower leaves (oblong rather than ovate), in the primary lateral veins much less densely arranged on the abaxial leaf surface, and in the large rhombohexagonal (rather than small ± circular) stylar region. Very similar to R. perkinsiae but distinguishable by the primary lateral veins much less prominent than the interprimaries on the abaxial leaf surface, and by the longer (14-17 cm vs. 10-12 cm) spadix. Based on material seen it appears that the spathe persists into fruiting before eventually rotting away. The spathe of R. perkinsiae falls early on during anthesis.
Philippines (Luzon, Mindoro, Negros, Samar). Endemic.
Steep forested valley, shaded vertical rock faces, cut-over forest on slopes near ridges.