Perennial tuberous herb; root stock send out many suckers, leaves and petioles usually purple; leaves long-petioled; petiole basally vaginate, sheathing; lamina large, ovate-triangular or round-ovate, with basal sinus, mottled in different colours; flowers axillary, numerous, unisexual in oblong spadix usually shorter than the erect spathe, green outside, pale green inside, caudate-acuminate; tube convolute, persistent, 2-4 times shorter than the oblong limb, purplish in throat; male inflorescence usually longer; perianth scaly or absent; stamens with fleshy connective bearing 2-3, small, anther cells, dehiscing by terminal slits; ovaries ovoid, 1-celled, stigma sessile, disciform, ovules many, orthotropous, parietal placenta; berries small, obconic or oblong, reddish-brown, many-seeded; seeds oblong, sulcate with copious albumen.