WordNet sense 1 (the traditional mistletoe of Christmas in America: grows on deciduous trees and can severely weaken the host plant):

Phoradendron flavescens, Phoradendron serotinum

WordNet sense 2 (small herb with scalelike leaves on reddish-brown stems and berrylike fruits; parasitic on spruce and larch trees):

Arceuthobium pusillum