The largest family of mistletoes, the Loranthaceae, has 73 genera and over 900 species. Molecular data show the mistletoe habit has evolved independently five times within the Santalales-first in the Misodendraceae, but also in the Loranthaceae and three times in the Santalaceae (in the former Santalalean families Eremolepidaceae and Viscaceae, and the tribe Amphorogyneae). Parasitism has evolved at least twelve times among the vascular plants. Further etymology is uncertain, but may be related to the Germanic base for 'mash'. 'Mistle' is common Germanic (Old High German mistil, Middle High German mistel, Old English mistel, Old Norse mistil). The word 'mistletoe' derives from the older form 'mistle' adding the Old English word tān (twig). Over the centuries, the term has been broadened to include many other species of parasitic plants with similar habits, found in other parts of the world, that are classified in different genera and families such as the Misodendraceae of South America and the mainly southern hemisphere tropical Loranthaceae. The eastern mistletoe of North America is similar, but has shorter, broader leaves and longer clusters of 10 or more berries. The eastern mistletoe native to North America, Phoradendron leucarpum, belongs to a distinct genus of the family Santalaceae.Įuropean mistletoe has smooth-edged, oval, evergreen leaves borne in pairs along the woody stem, and waxy, white berries that it bears in clusters of two to six. The genus Viscum is not native to North America, but Viscum album was introduced to Northern California in 1900.
A related species with red rather than white fruits, Viscum cruciatum, occurs in Southwest Spain and Southern Portugal, as well as in Morocco in North Africa and in southern Africa. The name mistletoe originally referred to the species Viscum album (European mistletoe, of the family Santalaceae in the order Santalales) it is the only species native to the British Isles and much of Europe. They are attached to their host tree or shrub by a structure called the haustorium, through which they extract water and nutrients from the host plant. Mistletoe is the common name for obligate hemiparasitic plants in the order Santalales.
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