Plants usually large and coarse, terrestrial, arising from a hypogean tuber or from a more or less elongate, hypogean or epigean caudex; petioles long, thick, sub-terete, vaginate below; blades sagittate, hastate, or trisect or pedatisect, the primary lateral nerves of the blades or their segments united to form a more or less distinct collective nerve; peduncles solitary or aggregate, mostly short; tube of the spathe ovoid or oblong, convolute, persistent, constricted at its apex, the limb oblong-cymbiform or oblong-lanceolate; spadix shorter than the spathe, the pistillate portion cylindric, densely many-flowered, narrowed upward, the sterile staminate part longer than the pistillate, narrowed above, the fertile staminate portion thick-cylindric, slightly narrowed upward, twice as long as the pistillate portion or longer; flowers unisexual, naked; stamens 4-6, connate to form a truncate-obpyramidal, 5-or 6-angulate synandrium truncate at its apex; anther cells obversely oblong-triangular or oblong, opening below the apex of the connective by a short slit; ovaries ovoid, coherent by the thickened, annuliform styles, 2-to 4-celled; ovules several or numerous, anatropous; stigma discoid or hemispheric-discoid, 3-or 4-lobate; berries cylindroid, crowned by the impressed stigma, 3-or 4-celled, the cells many-seeded; seeds ovoid, shorter than the funicles, the testa sulcate.