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

The limestone karsts of Southeast Asia and South China are a major biodiversity hotspot of global terrestrial biomes. With more than 130 described species, Paraboea has become one of the most characteristic plant groups in the Southeast Asian limestone flora. During the course of extensive field work on the limestone formations of southern and southwestern China, three unknown species of Paraboea were collected. Molecular phylogenetic analyses based on nuclear ITS and chloroplast trnL-F sequences strongly confirm the placements of the three new species in Paraboea sensu Puglisi et al. (Taxon 65:277-292. https://doi.org/10.12705/652.5, 2016). Moreover, these three novelties can be distinguished from known Paraboea species with distinct morphological characters, further supporting their recognition as new species. With the support of detailed morphological studies and molecular phylogenetic analyses, Paraboea dushanensis, P. sinovietnamica and P. xiangguiensis are recognized as three species new to science.