Southern range extension of the white fir dwarf mistletoe in Arizona

Discovery of a small isolated population of the white fir dwarf mistletoe, Arceuthobium abietinum f. sp. concoloris, in the Chiricahua Mountains of southeastern Arizona extends the southern distribution of this mistletoe 300 miles. The rare occurrence of the mistletoe in the southwest suggests that it once had a more southerly distribution but only survived past climatic changes in a few locations.