Erect, ascending, climbing or floating perennials, often robust, stoloniferous or not. Leaves spirally arranged or bifarious, subsessile or distinctly stalked, ovatelanceolate or oblong-lanceolate-linear, with or without a spirally coiled, tendril-like apex; their sheaths embracing the stem, either closed all round or more or less deeply split on the anterior side. Blade closely longitudinally nerved or subpenninerved; nerves connected by numerous short, often oblique transverse veinlets. Flowers arranged in terminal, sessile or peduncled panicles, sessile, actinomorphic, ♀ or unisexual, rather small. Perianth hypogynous, calycine or corolline. Tepals 6, 2-seriately imbricate, free or shortly connate, persistent. Stamens in ♀ and ♂ 6, free; anthers basifixed, 2-celled; cells bursting by an introrse longitudinal slit. Ovary in ♀ and ♀ superior, sessile, 3-celled; cells with a solitary ovule in the inner angle; stigmas 3 or one deeply 3-lobed stigma, sessile. Fruit drupaceous, indehiscent. Seeds or kernels 1-3; albumen copious; embryo small. Distr. Genera 3, in the tropics of the Old World, all of them in Malaysia.