Analysis of morphological characters of Arceuthobium apachecum and A. blumeri indicates there are several geographically consistent differences between these taxa, which supports their current classification at the specific level. Shoot height and perianth lobe number exhibited considerable geographic variation, and some morphological characters examined were continuous. Peak flowering and seed dispersal periods for these species differed slightly Altitudinal, seasonal, and latitudinal variations in flowering and seed dispersal were detected and may be responsible for the differences in phenology between these taxa.
Mathiasen, Robert L.
"Taxonomic studies of dwarf mistletoes (Arceuthobium ssp.) parasitizing Pinus strobiformis,"
Great Basin Naturalist: Vol. 42
, Article 16.
Available at: http://scholarsarchive.byu.edu/gbn/vol42/iss1/16