Herbaceous, perennial root-parasites without roots or chlorophyll, arising from underground tubers attached to the roots of the host. Leaves spiral or distichous, scale-like. Flowers unisexual. Male flowers: tepals 3-9; stamens 2 or 3(4). Female flowers: perianth segments 0 or 3; 3- or 4-merous; ovary ± inferior; style present or 0. Fruit a 1-seeded achene.