Using random amplification of polymorphic DNA for a taxonomic reevaluationof Pfitzer junipers

Van Melle (1947) proposed that juniper cultivars of the Pfitzer Group were of hybrid origin and ascribed the name Juniperus xmedia Melle. This purport ed hybrid of J. chinensis L. x J. sabina L. has not been accepted unanimous ly by the horticultural community. Random amplified polymorphic DNAs (RAPDs ) were used to analyze and establish new evidence for the hybrid origin of the Pfitzer Group, using both parents and seven cultivars of the Pfitzer Gr oup. Principal coordinate analysis (PCO) of 122 RAPD bands demonstrated tha t samples of J. chinensis cluster tightly together, as do the J. sabina sam ples. Cultivars of the Pfitzer Group lacked affinity with either species, b ut stood apart as a distinct cluster. The data support Van Melle's conclusi on that the Pfitzer Group is separate from J. chinensis and indicate hybrid origin from parents J. chinensis and J. sabina. We recognize Juniperus xpf itzeriana (Spath) Schmidt [Pfitzer Group] as the correct name for cultivars of Pfitzer junipers. Juniperus xmedia, proposed by Van Melle, was rendered illegitimate because of the earlier name J. media V.D. Dmitriev.