Maximum polyphyly: Multiple origins and delimitation with plesiomorphic characters require a new circumscription of Minuartia (Caryophyllaceae)

Minuartia is one of the larger genera of Caryophyllaceae with about 175 species distributed mainly in the Northern Hemisphere. The taxonomy of the genus has been studied by several authors, resulting in the recognition of numerous infrageneric groups. Previous phylogenies of the Caryophyllaceae showed that Minuartia is polyphyletic, but included only a limited sample of the genus. We here provide a molecular phylogeny of Minuartia including all infrageneric groups recognized in the last revision of the genus. We reconstructed the phylogeny of the genus using DNA sequences of nrITS and plastid matK from 160 ingroup and 105 outgroup samples. The evolution of the morphological character relevant for the delimitation of Minuartia (three styles plus three capsule valves/teeth) was reconstructed. Minuartia has been defined with a plesiomorphic character and is highly polyphyletic. All four subgenera fall into different lineages containing other genera of the family, and M subg. Minuartia, as by far the largest subgenus, falls into seven clades, which together do not form a monophylum. These clades are closely related to several other genera, e.g., Sagina, Colobanthus and Scleranthus. In several cases taxonomic groups below subgeneric rank are monophyletic. The type of Minuartia, M dichotoma, is part of a clade containing M sect. Plurinerviae and sect. Minuartia. We propose to retain this clade as Minuartia s.str. and to transfer the other species of Minuartia to the genera Cherleria, Eremogone, Facchinia, Mcneillia, Minuartiella, Mononeuria, Pseudocherleria, Rhodalsine, Sabulina and Triplateia.