An analysis of recent taxonomic concepts in wild potatoes (Solarium sect. Petota)

Abstract

Solanum L. sect. Petota Dumort., the potato and its wild relatives, contains 232 species, according to the latest taxonomic interpretation of Hawkes (1990). Section Petota is distributed in the Americas from the southwestern United States to southern Chile. This economically important group has attracted the attention of numerous taxonomists with various taxonomic philosophies. There are 531 validly published basionyms in the group, plus 67 nomina nuda or nomina dubia, and subsequent transfers to other ranks raise the number of names to 664. The taxonomy of sect. Petota has been dominated in recent years by J. G. Hawkes & J. P. Hjerting (co-workers) and C. M. Ochoa. The near simultaneous and independent publication of three recent books by these workers, treating the Bolivian species of sect. Petota, provides a novel opportunity to compare their taxonomic philosophies. Additionally, a recent independent treatment of all of the South American species by L. E. Gorbatenko provides a new interpretation of affiliations of species to series that is compared to the recent treatment of Hawkes and earlier treatments of S. M. Bukasov and D. S. Correll. These treatments differ in the placement of species into series, species boundaries, rank of infraspecific taxa, and hypotheses of hybridization. Our analysis illustrates the wide differences of taxonomic interpretation possible when independent workers treat the same material. The comparison provides insights into unresolved taxonomic questions in sect. Petota and indicates the need for a practical taxonomic resolution that will benefit plant breeders and other researchers on wild potatoes. Reasons for the discrepancies are discussed and suggestions for future research are provided.