Mistletoe

Mistletoe is the common name for a group of parasitic or hemiparasitic flowering plants, especially species in the genera Viscum, Phoradendron, and Arceuthobium.

Mistletoe is a common name for parasitic flowering plants that grow on tree branches. The best-known type is European mistletoe (Viscum album), an evergreen hemiparasite.

What it is

Mistletoe refers to many species in the families Santalaceae, Loranthaceae, and Misodendraceae. Most are hemiparasites: they photosynthesize but also draw water and nutrients from host trees. They grow as evergreen shrubs on branches, forming rounded clumps in tree canopies.

Why it matters

Mistletoe is ecologically important—its fruits and structure provide food and shelter for birds and wildlife, and in some habitats it is a keystone species. Culturally, it is famous for winter holiday traditions, especially the custom of kissing beneath it. However, all parts are poisonous to humans and animals.

Key details

Mistletoe species are found worldwide in temperate and tropical regions. European mistletoe (Viscum album) is native to Eurasia and grows on broadleaf trees like apple, oak, and willow. Its leaves, stems, and berries are toxic. In Canada, both native and introduced species occur, and it is familiar to readers through holiday customs and its effects on trees.