Tuber dirty pale yellowish, brownish, or orangish, yellow inside, globose, sometimes slightly subcylindric, with a deep central depression, 4-8 cm high (or more), 5-25 cm in diam., weighing up to 750 g (?or more), seasonally developing several offsets; offsets rhizomatous, long and thin, 2-27 × 0.4-1 cm, apically slightly thickened or not. Leaf solitary; cataphylls 3, to 25 cm, proximally pale pink, distally grading into off-white, covered with pale blackish green, elongate spots; petiole background color pale green, at base often pale pink or with a reddish brown or reddish hue, with many smaller and larger, partly or nearly entirely confluent, elliptic to narrowly elliptic, blackish green or paler green or rarely reddish brown spots and several small, white dots, intensity of color and extension of pattern variable, 20-190 cm, 1-5 cm in diam. at base, glabrous; leaf blade 100-200 cm in diam.; rachises broadly winged; leaflets paler green abaxially, green or grayish green adaxially, lanceolate to elliptic-lanceolate, more rarely elliptic, 11-48 × 2-11 cm, base decurrent, apex acuminate. Inflorescence solitary; peduncle colored as petiole but smaller, 25-100 cm, 0.8-2 cm in diam. at base. Spathe erect, convolute at base, outside pale green, toward base slightly darker, inside pale yellowish green, base sometimes ± maroon, cymbiform, ovate to ovate-lanceolate, 11-40 × 6-26 cm, basal convolute part 4-6 cm, base inside with many small, slightly elongate or irregularly ridge-shaped warts, apex acute-acuminate. Spadix developing considerable heat at female anthesis and producing a heavy, gaseous, nauseating stench, yellowish white or pale green, nearly as long as spathe, rarely distinctly shorter or slightly longer, 8-35 cm; flowers unisexual, naked; female zone cylindric or slightly obconic, 0.6-5 cm, 0.6-2.3 cm in diam. (including styles), flowers congested; ovary pale green, occasionally pale magenta-purple near style base, globose or slightly depressed, 1.5-2 mm high, 2-2.5 mm in diam., 1-loculed (rarely ?2-loculed), with 1 basal ovule; style green or magenta-purple, cylindric or conic, 1-2 mm; stigma globose or semiglobose, ca. 1 mm in diam., entire or with a shallow central depression or shallowly 2- or 3-lobed; lobes pale yellowish white, yellow, or brownish, rounded, scabrous, margin sinuous; sterile zone between female and male zones rarely absent, cylindric, 0.6-2 × 0.8-1.8 cm, staminodes congested; appendix fusiform or fusiform-conic, sometimes slightly laterally compressed, 3-17 × 0.9-5 cm, sometimes with a small stipelike part, glabrous, apex rounded or ± acute, base occasionally stipelike, at base sometimes with a few rounded staminodes or staminodal remnants, separated by small grooves; staminodes often with a droplet as on connectives at female anthesis, ivory-white or creamy orange, occasionally flushed with pale purple, ovate or diamond-shaped in cross section, semiglobose, 1-4.5 × 1-3.1 mm in cross section; male zone cylindric-fusiform or slightly obconic, sometimes slightly laterally compressed, 3.5-13 × 0.8-3 cm, flowers congested; male flowers consisting of (1-)3 or 4(or 5) stamens, ivory-white; stamens 2-2.2 mm high; filaments short, 0.75-1 mm, thick, connate, in lowermost flowers greatly enlarged and with reduced thecae, grading into staminodes; anthers with a rounded apex or subtruncate, 1-1.3 mm high, 1-1.75 mm in diam.; pores apical, elongate; connectives often with a clear, slightly sticky droplet at female anthesis. Infructescence cylindric, ca. 10 cm. Berries 1-seeded (rarely ?2-seeded), bright red, ca. 1 cm. Seeds silvery gray with small, black dots, elliptic-ovoid, 6-9 × 3-5 mm. Fl. Jun-Aug, fr. Nov-Dec.