Rhizome monopodial, with 2 vascular bundles in cortex. Shoots short, with several leaves; flowering stems usually elongated, with several spathes. Leaves linear, with 3-11 parallel veins, margin entire or rarely minutely denticulate; sheaths membranous or subleathery, with an auricle, ligulate. Spadix axillary, sessile, axis flattened, without or only with inconspicuous projections (retinacula). Plants monoecious; flowers unisexual, small. Anthers 2-celled. Style short; stigmas 2, filiform or subulate. Fruit ovoid, with a short beak.

About 12 species: best represented along shores of N temperate regions; five species in China.