Resurrection of Sorbus tapashana (Rosaceae) based on molecular and morphological evidence

Abstract

Sorbus tapashana (Rosaceae) from Taibai Shan, Qinling, China, has been treated as a synonym of S. tianschanica. Both species belong to a distinctive group characterized by white tomentose buds, relatively large flowers, and red fruits. However, these two species do not cluster together in the plastome-based phylogenetic analysis. Morphologically, S. tapashana differs from S. tianschanica by its persistent white tomentose on the peduncle, pedicels, rachis, both sides of the midrib on abaxial surface, its leaflets with 31–51 teeth on each side and much smaller corymbs and fruits. Therefore, S. tapashana is reinstated as a distinct species here.