Abstract
One new tribe (Plagiolobeae), one new species (Plagioloba derakii) together with two new combinations (P. persica and P. clavata) are established within Brassicaceae based on a decisive consideration of molecular phylogenetic dataset, morphological characters, fruit septum nature, as well as seed microsculpturing features. Results distinctly justified Arabis ottonis-schulzii as a synonym of Conringia persica and further molecular analyses proved its placement as a member of genus Plagioloba. It is also placed in a new tribe Plagiolobeae as close relatives of Conringieae and Coluteocarpeae. Finally, the diagnostic morphological characters separating the new tribe from the previously assigned tribe (Conringieae) are also discussed.