Treelike herbs, perennial, from corm [rhizome] [corm]. True aerial stems absent. Leaves basal, in several ranks, differentiated into basal sheath, petiole, and blade; sheaths overlapping, forming unbranched pseudostem, open, ligule absent; summit of petiole not differentiated; blade with lateral veins parallel, diverging from prominent midrib. Inflorescences 1 per aerial shoot, projecting from tip of pseudostem, pedunculate racemes of 12--20-flowered monochasial cymes (cincinni); bracts of main axis enclosing cincinni. Flowers unisexual (proximal flowers pistillate, distal flowers staminate), bilaterally symmetric; sepals and petals differentiated, sepals 3, petals 3, 3 sepals and 2 petals fused, remaining petal distinct; fertile stamens 5(--6), not petal-like; anthers 2-locular; occasionally 1 rudimentary staminode; ovary inferior, 3-carpellate, 3-locular, all locules fertile; placentation axile; ovules many per locule; style terminal, filiform; stigma 3-lobed. Fruits berries; sepals not persistent in fruit. Seeds: aril absent; endosperm copious; perisperm copious; embryo straight. x = 9, 10, 11.