International Aroid Society

EPIPREMNUM
Epipremnum Schott, Bonplandia 5 (1857) 45; Schott, Gen. Aroid. (1858) t.79; Engl. in DC., Monogr. Phanerogam. 2 (1879) 248; Engl. in Beccari, Malesia 1 (1883) 272; Engl. in Engl. & Prantl, Nat. Pflanzenfam. 2(3) (1889) 120; Hook.f., Fl. Brit. Ind. 6 (1893) 548; Engl. & K. Krause, in Engl., Pflanzenr. 37(IV.23B) (1908) 54; Merr., Enum. Philip. Fl. Pl. (1923) 177; Ridl., Fl. Mal. Pen. 5 (1925) 119; Henderson, Malay. Wild Fl. (Monocots) (1954) 235. -- Type: E. mirabile Schott (= E. pinnatum (L.) Engl.). Anthelia Schott Ann. Mus. Bot. Lugd.-Bat. 1: 127 (1863). -- Type: Anthelia nobilis Schott

Distribution -- Approximately 15 species from Japan (Ryukyu Islands) to Australia (Queensland) and India (Manipur) to Oceania (Cook Islands: Rarotonga).
Habitat -- Bole climbers in low to mid-elevation evergreen forest, occasionally persisting in disturbed areas or growing lithophytically in exposed situations.

Slender to gigantic homophyllous (but leaf laminae occasionally becoming increasingly pinnatifid and perforated towards maturity) root-climbing lianes to 20 m. Seedling stage mostly not observed. Pre-adult plants forming modest to extensive terrestrial colonies. Adult plants with physiognomically monopodial clinging stems rooting along their entire length, free stems usually not occurring (but see E. giganteum) other than as a result of external physical damage (e.g. weight of the inflorescences and infructescences) and then usually soon climbing again. Flagellate foraging stems occurring in some species (maybe all, but often not observed), these often exceedingly long, reaching the ground then rooting, foraging and climbing again. Growing stems with internodes separated by variously prominent leaf scars, stems smooth, asperous or furnished with prominent irregular whitish longitudinal crests, older stems sub-woody or somewhat to exceptionally corky or with distinctive matt to sub-lustrous pale brown papery epidermis, with or without variously textured prophyll, cataphyll and petiolar sheath fibre; aerial roots of two types, clasping roots sparsely to densely arising from the nodes and internodes, strongly adherent to substrate, feeding roots rather uncommon, often absent, usually strongly adherent to substrate, more rarely free, both root types pubescent, clasping roots later corky, feeding roots later becoming woody and prominently lenticellate. Cataphylls and prophylls sub-coriaceous to membranaceous, soon drying and falling or degrading to variously textured sheaths and fibres, where present these variously clothing upper stem before eventually decaying and falling. Foliage leaves evenly distributed or scattered on lower stem and evenly distributed to clustered distally. Petiole canaliculate to weakly carinate with apical and basal genicula; petiolar sheath prominent, at first membranaceous to coriaceous, soon completely or along the margins drying chartaceous, sometimes degrading to untidy variously netted or simple fibres and later variously falling to leave a scar or disintegrating marginally or completely. Lamina sub-membranaceous to stiffly chartaceous or coriaceous, entire to regularly or irregularly pinnatifid, divisions pinnatifid to pinnatisect (Stearn, 1992: 324), occasionally midrib ± naked between segments, lamina rarely with minute to somewhat well developed pellucid dots adjacent to the midrib, these dots often perforating and enlarging, sometimes extending to lamina margin (fenestrations then often additional to fully developed pinnae); primary venation simple to compound and pinnately arranged, interprimaries mostly present, subparallel to primaries and sometimes indistinguishable from them (E. giganteum); secondary venation striate to reticulate, tertiary venation reticulate to tesselate, reticulate higher venation restricted to species with dissected or fenestrate leaves. Inflorescences solitary to several together, first inflorescence subtended by a (usually fully developed) foliage leaf and/or a very swiftly disintegrating cataphyll, subsequent inflorescences subtended by a prophyll and cataphyll, inflorescences at anthesis almost naked by disintegration of subtending cataphyll to partially to almost completely obscured by netted and sheet-like fibres. Peduncle terete to laterally compressed. Spathe canoe-shaped, stoutly to rather weakly beaked, gaping to opening almost flat at anthesis and then deciduous before anthesis is complete, stiff to rather soft-coriaceous, dirty-white, greenish or yellow. Spadix variously cylindrical, sessile, rarely stipitate, bluntly tapering towards the apex, base often slightly obliquely inserted. Flowers bisexual, naked; ovary variously cylindrical, often laterally compressed and variously irregularly angled, those upper- and lowermost on the spadix often sterile and bereft of stigma; placenta one; placentation intrusive parietal; ovules 2--8, anatropous; stylar region prominent to massive; stigma puncatate to linear, sticky at female anthesis, orientation circumferential or longitudinal; stamens 4; filaments strap-shaped; anthers prominently exserted from between ovaries at male anthesis, dehiscing by a longitu-dinal slit. Fruit with stylar region greatly enlarged, transversely dehiscent, the abscission developing at the base of the massive stylar region and this falling to expose the ovary cavity with the seeds embedded in variously coloured sticky pulp. Seeds curved, often strongly so, albuminous, testa bony and smooth to ornamented. Pollen fully zonate, hamburger-shaped, medium-sized (36--44 µm), exine foveolate-fossulate, psilate at periphery, apertural exine coarsely verrucate. 2n = 60 (56, 84).
DISTRIBUTION. Indo-Malesia to Japan (Ryukyu Islands), Australia to tropical western Pacific.