Appressed epiphytic climber or sometimes terrestrial, rooting at the nodes; juvenile plants terrestrial, with long internodes; preadult plants with increasingly longer internodes; adult plants with internodes short, unbranched to branched; terrestrial plants with the STEMS reclining in age. LEAVES spiral or distichous, erect-spreading; petioles about equaling the blades, amplexicaule at base, sheathed throughout much of their length, geniculate at apex; the sheath persistent or deciduous; blades oblong to oblong-elliptic, typically drying dark, rarely pale green, slightly unequal at the base, sometimes slightly inequilateral; midrib sunken above, prominently raised below; primary lateral veins numerous, usually closely spaced, spreading nearly straight or slightly arcuate to the margins, lacking collective veins; interprimary veins numerous, typically much less conspicuous than primary lateral veins. INFLORESCENCE erect, much shorter than the leaves; peduncle short, longer or shorter than the spathe; spathe broadly ovate or oblong-ovate, abruptly cuspidate, moderately coriaceous, longitudinally veined, typically white or pink, soon deciduous; spadix sessile or stipitate, cylindroid, slightly tapered toward apex or toward both ends, densely many-flowered. Flowers naked, perfect or rarely with only pistillate flowers at the base, arranged in a series of spirals; stamens 4, the filaments broad, complanate, narrowed to the slender, acuminate connective; anthers rather broad, the thecae ellipsoid, longer than the connective, dehiscent by lateral slits; ovary 4-angled, 2-celled, the ovules several or numerous per cell, amphitropous; style thicker than the ovary, the stigma usually slit-like with or without a weakly raised rim, persisting in fruit. INFRUCTESCENCES with berries small, cylindric-prismatic, truncate, usually not colorful, 10-12 seeded; seeds attached by short funicles, ventrically imbricate, rounded-reniform, lentiform, the testa minutely verruculose.
HABIT : evergreen, usually climbing herbs, producing flagelliform shoots. LEAVES : many, distichously arranged. PETIOLE : geniculate apically, sheath long, persistent to marcescent. BLADE : oblong-elliptic, ± oblique, always entire; primary lateral veins pinnate, numerous, running into ± distinct marginal vein, secondary and tertiary laterals parallel-pinnate, higher order venation transverse-reticulate. INFLORESCENCE : usually solitary. PEDUNCLE : shorter to longer than petiole. SPATHE : broadly ovate or oblong-ovate, abruptly cuspidate, yellowish white, cream, purplish or pink within, caducous after anthesis. SPADIX : long-stipitate to sessile, cylindric-conic, basal flowers sometimes sterile or female and scattered. FLOWERS : bisexual, perigone absent. STAMENS : 4, filaments linear-oblong, flattened, connective slender, thecae ovoid to ellipsoid, dehiscing by longitudinal slit. POLLEN : extruded in strands, fully zonate or inaperturate, hamburger-shaped or ellipsoid to oblong, medium-sized (mean 47 µm., range 34-57 µm.), exine densely to sparsely foveolate and nearly psilate to obscurely fossulate or verrucate. GYNOECIUM : compressed obconic to cylindric, ovary 2-locular, ovules usually numerous per locule, rarely few (R. venosa), anatropous to hemianatropous, funicle fairly long, placenta axile, rarely subbasal, style well-developed, broader than ovary, prismatic, truncate to convex apically, stigma elliptic to linear, usually oriented in long axis of spadix. BERRY : cylindric-prismatic, truncate, many- to few-seeded. SEEDS : rounded-reniform, flattened, testa brittle, very hard, smooth or with verrucose crest, embryo rather large, strongly curved, endosperm present but sparse.
Evergreen, climbing hemiepiphytes; trichosclereids abundant; leaf blades entire, oblong-elliptic, secondary and tertiary veins parallel-pinnate, fine venation transversely reticulate; spathe deciduous after flowering; flowers bisexual, perigone absent. Differs from Stenospermation in climbing hemiepiphytic habit, axile placentation, seeds flattened, rounded-reniform. Differs from Monstera in having entire leaf blades, seeds less than 3 mm long and lenticelular and in the presence of endosperm.