Robust, short or very tall perennial herbs, often aromatic, from fleshy rootstocks, sometimes with tubers. Stems simple, rarely branching, leafy; occasionally 0. Leaves basal or cauline, sessile or petiolate, sheathing, usually distichous, occasionally spirally arranged, closely pinnately-veined from a strong midrib. Flowers large, usually bisexual, often zygomorphic, in terminal spikes, racemes, panicles, or solitary; each flower or flower-cluster with conspicuous bract. Perianth-segments 6 in 2 whorls; sepals 3, connate in a 3-toothed tube or spathe-like; petals 3, ± connate in a slender, 3-lobed tube, dorsal lobe often longer than lateral ones. Fertile stamen 1; staminodia 1-4, usually large and showy, occasionally joined in a labellum; filament of stamen slender, joined to perianth at base and occasionally to staminodia; anther 2-locular. Ovary inferior, 3-(2)-locular with axile placentae or 1-locular with parietal or rarely basal placentae; ovules usually many; style slender, filiform, ± enveloped in a channel of the filament and passing between the pollen-sacs of the anther; stigma usually entire, protruding beyond anther. Fruit a loculicidal capsule, or fleshy and berry-like, usually crowned by remains of perianth. Seeds many, arillate. About 45 genera and 1400 spp., in tropics and subtropics.