Book excerpt: Contents: generalized life cycle; sexual reproductive biology; mechanism and trends of evolution; biogeography and paleogeographic history; host relationships; ecological relationships; biotic associates; host-parasite physiology; anatomy of the dwarf mistletoe shoot system; endophytic system; pathogenic effects; control; systematics: philosophy, problems, and criteria for classification; molecular systematics; formal taxonomy. Extensive bibliography. Scientific and common names; collecting and curating techniques; herbaria consulted; specimens examined; glossary; subject and species indexes.