Typification of Echinacea purpurea (L.) Moench (Heliantheae: Asteraceae) and Its Implications for the Correct Naming of Two Echinacea Taxa

A thorough investigation of relevant nomenclatural types and descriptions reveals that the name Echinacea purpurea (L.) Moench, which was lectotypified by McGregor in 1968, has been consistently misapplied since 1903 to a taxon distinctly different from that of its modern lectotype and of the original Linnaean concept. Linnaeus's original concept of Rudbeckia purpurea, maintained by Candolle as Echinacea purpurea when he segregated E. serotina (Nutt.) DC., is the species now known as E. laevigata (C. L. Boynton & Beadle) S. F. Blake. Technically, therefore, the correct name for the species currently called E. laevigata is E. purpurea (L.) Moench, and the correct name for the species currently called E. purpurea is E. serotina (Nutt.) DC., for which a lectotype is designated. Conservation of the name E. purpurea in the sense of its current application, which also preserves the usage of E. laevigata, is proposed in a separate article (see Binns & al., p. 1199, this issue).