Lianas, very large to gigantic, to 40 m, very robust. Stem cylindric, very thick, 3-4 cm in diam., internodes 1-6 cm. Leaves dense, spiro-distichous; petiole green, canaliculate, 50-70 cm; petiolar sheath extending to ca. halfway, soon marcescent; leaf blade light green abaxially, green adaxially, ovate-oblong, very large, 50-70[-90] × 28-50 cm, stiffly leathery, base cordate, margin entire, apex abruptly acuminate; primary lateral veins 10-13 on each side, diverging at 80-90° from midrib. Inflorescences in fascicles of up to 4 inflorescences per synflorescence at tips of primary clinging shoots, appearing axillary. Peduncle green, 15-18 × ca. 2 cm. Spathe initially inrolled, white-green, afterward spreading, light yellow, opening deep yellow, oblong-cymbiform, 20-27 × ca. 16 cm, very thick (ca. 2 mm when dry). Spadix sessile, yellow-green, when dry green-black, cylindric, 18-25 × ca. 2.5 cm, base oblique, apex obtuse. Stamens 4; filaments compressed, 2-3 × 0.5-1 mm; anthers yellow, small. Ovary tetragonal-or hexagonal-cylindric, ca. 7 mm; stigma sessile, punctiform; ovules narrowly ellipsoid or cylindric; funicle long and thin, base hairy. Infructescence broadly cylindric, up to 30 × 5 cm. Fl. Apr-Aug.
Home