A new synonym of Enkianthusperulatus (Ericaceae) in East Asia, based on morphological and molecular evidence

Enkianthuscalophyllus was once treated as a synonym of E.serrulatus. However, field observations indicate that E.calophyllus is distinct from E.serrulatus but resembles E.perulatus in flowers, leaves, fruits and seeds. Hence, a taxonomic revision of these species was conducted based on morphological comparisons of flowers, leaves, fruits and seeds, as well as molecular analyses of nuclear ribosomal internal transcribed spacer (nrITS) and six plastid DNA markers (psbA-trnH, rpl32-trnL, trnL-trnF, rps16-trnQ, psbJ-petA and matK). The morphological and molecular results reject the synonymization of E.calophyllus with E.serrulatus, and instead show it to be placed in a clade with E.perulatus. Based on molecular evidence and a reassessment of the morphology we synonymize E.calophyllus with the older name E.perulatus.