Herbs or shrubs; leaves spiralled or opposite; stipules none; blades simple; flowers bisexual or unisexual usually axillary; tepals 3-5; bracts and tepals more or less scarious; stamens 1-5; stigmas 1-4; fruit utricular or berrylike. About 40 genera and nearly 500 species, cosmopolitan in warm regions. Seven genera in Guam two native and five introduced.