Arceuthobium microcarpum (Engelm.) Hawksw. & Wiens

Arceuthobium microcarpum (Engelm.) Hawksw. & Wiens. Arceuthobium microcarpum is a species of flowering plant in the family Santalaceae endemic to the coniferous forests of Arizona and New Mexico. As with other species of dwarf mistletoe, A. microcarpum parasitizes several species of conifers, relying on the host plant for water and nutrients. There are two subspecies: A. microcarpum subsp. microcarpum, commonly known as western spruce dwarf mistletoe, which parasitizes spruce trees, and A. microcarpum subsp. aristatae, commonly known as bristlecone pine dwarf mistletoe, which parasitizes bristlecone pine trees. Because of its extremely limited range, A. microcarpum is considered an imperiled species.