ITS-based phylogenetic backbone of Arabideae that focuses on the placement of Arabis watsonii. Shown is the Bayesian maximum clade credibility tree with posterior probability values > 0.5. Highlighted part of the tree, (magnified on the left), is the Arabis hirsuta aggregate and its relatives. Color codes: Green = A. hirsuta aggregate, red=the closest relatives of the A. hirsuta aggregate, blue = A. watsonii. Clade names follow Karl and Koch (2013).