A REEXAMINATION OF SPECIES BOUNDARIES BETWEEN SOLANUM-MEGISTACROLOBUMAND S-TORALAPANUM (SOLANUM SECT PETOTA, SERIES MEGISTACROLOBA) - MORPHOLOGICAL DATA

Solanum megistacrolobum and S. toralapanum are two phenetically simila r wild potato (Solanum sect. Petota) species, classified in series Meg istacroloba, that together are distributed from southern Peru to north western Argentina. They have variously been synonymized, recognized as varieties of S. megistacrolobum, or recognized as distinct species. T his study examines 26 morphological characters of 115 living accession s of these two species, plus six accessions of two related species in series Megistacroloba, S. boliviense and S. sogarandinum. All measurem ents were taken from living accessions planted in a common garden plot . Solanum megistacrolobum and S. toralapanum could be distinguished ph enetically only by a combination of the 21 characters that showed stat istically significant differences between the two taxa. No individual characters provided consistent discrimination, and there was frequent overlap of ''species-specific'' characters between taxa. Our results m ost closely fit the contemporary treatment of S. megistacrolobum and S . toralapanum at the varietal level.