Rhaphidophora tetrasperma Hook.f.

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

Diagnostic

Petiolar sheath extending to base of apical geniculum, lamina sparsely to ± entirely deeply pinnatipartite to nearly pinnatisect, occasionally with large rhombic perforations adjacent to mid-rib. R. tetrasperma most closely resembles R. nicolsonii but may be distinguished readily on petiole sheath and leaf lamina characters.

General Description

Small to medium-sized, rather slender, semi-pachycaul, heterophyllous liane to 5 m; seedling stage a non-skototropic shingling juvenile shoot; pre-adult plants very rarely forming terrestrial colonies; LEAVES: adult shoot architecture comprised of elongated, weakly clinging, physiognomically monopodial, flexuous, moderately leafy, non-flowering stems and weakly adherent or, more commonly, free lateral flowering stems; stems smooth, without prophyll, cataphyll and petiolar sheath fibre, internodes to 14 x 1 cm, separated by prominent straight leaf scars; flagellate foraging stems not observed; clasping roots sparsely produced from nodes and internodes; feeding roots stout, produced singly or in pairs from most nodes of free shoots; leaves weakly spiral-distichous; cataphylls and prophylls membranous, soon drying and falling; petiole shallowly grooved, 10-34 x 0.2-0.4 cm, smooth, apical and basal genicula slightly prominent; petiolar sheath prominent, extending to base of apical geniculum, soon falling to leave a prominent, slightly corky scar; lamina sparsely to ± entirely deeply pinnatipartite to nearly pinnatisect, occasionally with large rhombic perforations adjacent to mid-rib, 12-42 x 9.5-38 cm, broadly ovate to ovate-lanceolate, thinly coriaceous, base truncate or very weakly cordate, apex acute to acuminate, individual pinnae up to 6 cm wide; mid-rib prominently raised abaxially, slightly sunken adaxially; primary venation pinnate, raised abaxially, slightly impressed adaxially; interprimaries diverging from primaries, much less prominent, slightly raised abaxially, very slightly impressed adaxially; secondary venation weakly reticulate, very slightly raised; tertiary venation barely visible; INFLORESCENCE few together, subtended by two prominent cataphylls, these soon falling; peduncle terete, 2-2.5 x 0.3-0.4 cm; spathe canoe-shaped, 3-3.5 x 0.8-1.5 cm, stiffly fleshy, apparently falling swiftly, white with adherent black cataphyll remnants; spadix cylindrical, sessile, inserted slightly decurrently on peduncle, 3-3.5 x 0.75 - 1 cm, white; stylar region well developed, mostly rhombohexagonal, c.c. 2 x 2 mm, truncate, margins deflexed; stigma elliptic, longitudinally orientated, c.c. 1 x 0.2 mm; anthers exserted at anthesis; INFRUCTESCENCE not observed.

Habitat

Disturbed rather dry to moist or wet forest on sandstone and granite.

Distribution

Peninsular Malaysia (Kelantan, Perak) and southern Thailand