Mistletoe is the common name for most obligate hemiparasitic plants in the order Santalales. Mistletoes attach to and penetrate the branches of a tree or shrub by a structure called the haustorium, through which they absorb water and nutrients from the host plant. 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 even families — such as the Misodendraceae and the Loranthaceae.