When the sticky berry (actually not a
true berry, since several other organs contribute to the fruit) of Viscum album
(Viscaceae) attaches to a host branch, it initially elongages its hypocotyl. Subsequently
a disk like structure, the primary haustorium, develops, which allows the plant to
penetrate the host tissue. After being established within the host tissue, the external
parts of the seedling will die. It may take several years until a first mistletoe shoot
reappears from the host branch. More information on parasitic plants, including Viscaceae, see Weber (1993): Parasitismus von Blütenpflanzen, Wissenschaftl. Buchges., Darmstadt (UB Marburg: Biol 270, Bibl. Fb Biologie: G 860:9)