Most people know mistletoe (Viscum album) primarily as a plant to hang up and kiss under at the holidays. But in its natural environment, mistletoe is a hemiparasite (a parasitic plant that is capable of some photosynthesis), latching onto trees and extracting water and nutrients from them. Now, two independent studies reported in Current Biology on May 3 show that mistletoe’s parasitic lifestyle has led the species to a rather surprising evolutionary loss. Mistletoe lacks key components of the cellular machinery other organisms depend upon to convert glucose into the energy-carrying molecule ATP.