HABIT : evergreen, robust to gigantic herbs (to 4m), rhizome thick, subterranean, spreading, terminal shoot forming massive banana-like pseudostem formed by the lower part of petiole sheaths. LEAVES : several in terminal crown. PETIOLE : very long, free apical part relatively short, sheath extending for most of petiole length. BLADE : very large, subtriangular to sagittate, acute; basal ribs well-developed, primary lateral veins pinnate, forming submarginal collective vein very near to margin, 3-4 marginal veins also present, secondary lateral and higher order venation densely parallel-pinnate. INFLORESCENCE : 1-2 in each floral sympodium. PEDUNCLE : erect, bent downwards in fruit. SPATHE : erect, constricted between tube and blade, tube convolute, oblong-ellipsoid, green, persistent, blade longer than tube, narrowly boat-shaped, acuminate, gaping at anthesis, cream-coloured, marcescent, later deciduous. SPADIX : shorter than spathe, sessile, free, differentiated into 4 zones, basal female zone with cuneiform staminodes scattered between gynoecia, separated from male zone by narrower zone of sterile male flowers, male zone thicker, subcylindric-conoid, terminal zone composed of sterile male flowers. FLOWERS : unisexual, perigone absent. MALE FLOWER : 4-6-androus, stamens connate, synandrium truncate, connective very broad, thecae lateral, sessile, dehiscing by short longitudinal slit. POLLEN : inaperturate, ellipsoid, medium-sized (mean 45 µm.), exine subverrucate or obscurely foveolate or punctate. LOWER STERILE MALE FLOWERS : synandrodium truncate, subhexagonal becoming narrowly rhomboid to trapezoid towards male zone. UPPER STERILE MALE FLOWERS : composed of 3-6 obpyramidal, truncate staminodes, irregularly connate or merely crowded together. FEMALE FLOWER : gynoecia surrounded by irregularly scattered, obpyramidal, truncate staminodes, ovary shortly ovoid to globose, 1-locular, ovule 1(-2), orthotropous, funicle thick, short, placenta basal, style very shortly attenuate, stigma rather broad, shallowly 3-6-lobed. BERRY : borne in subcylindric, pendent infructescence enclosed in persistent spathe tube, berries very large, compressed-obovoid to -globose, bright yellow, pericarp fleshy. SEED : large, compressed-obovoid, testa thin, ± smooth, embryo very large, plumule exceptionally well-developed with several leaf primordia, endosperm absent.