Twining herbaceous parasites. Stem slender, yellowish-brown or reddish-purple or with violet spots, attached to host by haustoria; spirally twining round the host, sometimes interlaced. Leaves reduced to small membranous scales. Flowers small, white to yellowish white or with violet spots usually arranged in cymose clusters or umbel-like cymes. Sepals mostly fleshy, gamosepalous, 4-5 (-6) lobed. Corolla tubular, 4-5 (-6) lobed, often with minute scales. Scales membranous or petaloid, equalling the number of stamens, attached to the corolla tube below each filament, simple or bind, filmbriate dentate or fimbriate-ciliate, forming a fringed or fimbriate ring-like structure inside the corolla tube. Stamens sessile or with filament, 5(-4), inserted in the throat, alternating with the corolla lobes. Ovary 2-locular, ovules 2 in each locule; style 1-2, free or united or obsolete; stigmas capitate or linear-elongated or oblong. Fruit a capsule, with or without intrastylar opening, 4-seeded or less by abortion, remaining closed or opening with a definite or irregular line of circumscission near its base. Embryo without cotyledons.