Three new species of Primulina (Gesneriaceae) from limestone karsts of China based on morphological and molecular evidence.

Background: With more than 160 described species, Primulina is one of the most characteristic plant groups of the Sino-Vietnamese limestone flora. In our continous botanical inventory of the limestone flora of South China, we collected three new Primulina species not identifiable to known species.

Results: Molecular phylogenetic analyses based on nuclear ITS and chloroplast trnL-F and trnH-psbA sequences strongly support the placement the three new species in Primulina. In addition to morphological differences, DNA sequences of all these three new species show substantial divergencies, sustaining the recognition of these three new species.

Conclusions: Based on morphological and molecular data, we describe and illustrate three new Primulina species: P. maculata, P. pengii, and P. yangshanensis.