Systematics of the Iranian genera Aphanopleura, Demavendia, Haussknechtia, Psammogeton, and Zeravschania (Apiaceae tribe Pimpinelleae)

Previous molecular phylogenetic investigations of Apiaceae tribe Pimpinelleae have focused primarily on its largest genus Pimpinella and its closest allies. The monophyly and phylogenetic placements of five Iranian genera of the tribe have not been addressed sufficiently (Aphanopleura, Demavendia, Haussknechtia, Psammogeton, and Zeravschania). To examine relationships, a nrDNA ITS matrix including 169 accessions representing 49 genera of Apiaceae (including 10 Iranian taxa not analyzed previously) and a cpDNA rps16 matrix containing 37 accessions representing 24 genera of the family, representing the greatest sampling to date of the aforementioned genera, were subjected to phylogenetic analyses using Bayesian inference and maximum parsimony methods. The trees obtained showed a close affinity among the examined species of Aphanopleura, Psammogeton and several species of Trachyspermum. Neither Aphanopleura nor Psammogeton resolved as monophyletic, and A. leptoclada allied with Pimpinella. The genera Demavendia, Haussknechtia and Zeravschania also comprised a well-supported clade, with Demavendia and Haussknechtia (in the ITS trees) arising from within a paraphyletic Zeravschania. To recognize monophyletic genera, one new combination is proposed in Pimpinella and six new combinations are proposed in Psammogeton. A broader circumscription of Zeravschania to include Demavendia and Haussknechtia may also be warranted, but must await further study.