title: Species delimitation in the Ponto-Caucasian Viola sieheana complex, based on evidence from allozymes, morphology, ploidy levels, and crossing experiments
abstract: Information from allozymes, ploidy levels, morphology, cross-compatibility and biogeography suggests that the easternmost occurrences of the Ponto-Caucasian Viola sieheana should be considered to belong to a separate species, V. caspia. Morphological characters delimitating V. sieheana and V. caspia are presented and discussed. The main distribution of V. sieheana s. str. is in the eastern Balkans, Turkey, Cyprus, and The Lebanon, and of V. caspia in the Caspio-Caucasian region westwards to Crim
journal: Plant Systematics and Evolution