a family of dicotyledonous plants including hemiparasitic shrubs or undershrubs that live on the branches, the trunks, or—less often—the roots of trees or shrubs. The leaves, which are generally evergreen and leathery, are sometimes reduced to scales. The small and usually regular flowers are bisexual or unisexual; they are gathered in inflorescences. The gynoecium consists of three or four carpels, and the ovary is inferior. The fruit is a berry or, less commonly, a drupe. The berries contain a sticky substance, viscin, which helps the seeds of the fruit, which are disseminated by birds, to adhere to the bark of trees.
There are approximately 40 genera, comprising as many as 1,400 species. The plants are found mainly in the tropics. The USSR has four species from the genera Viscum, Loranthus, and Arceuthobium. The last genus has small scalelike paired leaves and parasitizes juniper in the Crimea, western Transcaucasia, and Middle Asia.