The Classification of California Viscaceae: An Alternative Perspective

Abstract

Abstract The classification of Viscaceae in the second edition of the Jepson Manual (TJM2) differs radically from that in the first edition of the Jepson Manual (TJM1). The number of species of Arceuthobium M. Bieb. was reduced from 12 in TJM1 to three in TJM2, and for Phoradendron Nutt. reduced from seven species to four. The TJM2 treatment is conservative in regards to these taxa, and disregards many morphological, phenological, and other physiological discontinuities (e.g., host preferences) among the Viscaceae of California that have been consistently reported in the scientific literature since the 1960s. The species accepted in TJM2 have widespread geographical distributions containing distinct lineages, some of which we consider different species, and other lineages that may be considered cryptic taxa. These taxa are distinct enough, based on differences in morphology, phenology, host specificity, and geographic isolation, to warrant classification as species or subspecies. The taxonomic recognition...