Mistletoe is the common name for obligate hemi-parasitic plants in several families in the order Santalales. These plants grow attached to and penetrating within the branches of a tree or shrub by a structure called the haustorium, through which they absorb nutrients from the host plant. The name was originally applied to Viscum album (European Mistletoe, Santalaceae), the only species native in Great Britain and much of Europe. European mistletoe, Viscum album is readily recognized by its smooth-edged oval evergreen leaves borne in pairs along the woody stem, and waxy white berries in dense clusters of 2 to 6. In America the genus Viscum does not grow wild but the Eastern Mistletoe (in the genus Phoradendron) is similar, but has shorter, broader leaves and longer clusters of 10 or more berries. Viscum album is a poisonous plant that causes acute gastrointestinal problems including stomach pain, and diarrhea along with low pulse.
Contributions by MPF, Curtis Clark, and Plantsurfer.