Arceuthobium monticola

Arceuthobium monticola is a species of dwarf mistletoe known as western white pine dwarf mistletoe. It is a small shrub that grows on and parasitizes a small number of conifer species, primarily western white pines (Pinus monticola). It is endemic to the Klamath Mountains of northern California and southern Oregon, which has been identified as a major center of dwarf mistletoe biodiversity. This species impacts the ecology of coniferous forests significantly, negatively affecting the health of host trees but also creating valuable microhabitats for wildlife by inducing witch's brooms....read more on Wikipedia.