Arceuthobium abietinum

Arceuthobium abietinum, commonly known as fir dwarf mistletoe, is a species of dwarf mistletoe. It is native to western North America from Washington to New Mexico to northern Mexico, where it lives in coniferous forests as a parasite on various species of fir, particularly white fir, giant fir, and red fir, and less commonly on species of pine and spruce. There are four recognized varieties of A. abietinum, largely distinguished by their host preferences and geographic ranges. Largely because of its impacts on host trees, including the production of witch's brooms, A. abietinum significantly impacts forest ecology where it is present.

from Wikipedia