Karst ecosystems in southern China are species-rich and have high levels of endemism, yet little is known regarding the evolutionary processes responsible for the origin and diversification of karst biodiversity. The genus Primulina (Gesneriaceae) comprises ca. 170 species endemic to southern China with high levels of ecological (edaphic) specialization, providing an exceptional model to study the plant diversification in karsts. We used molecular data from nine chloroplast and 11 nuclear regions and macroevolutionary analyses to assess the origin and cause of species diversification due to palaeoenvironmental changes and edaphic specialization in Primulina. We found that speciation was positively associated with changes in past temperatures and East Asian monsoons through the evolutionary history of Primulina. Climatic change around the mid-Miocene triggered an early burst followed by a slowdown of diversification rate towards the present with the climate cooling. We detected different speciation rates among edaphic types, and transitions among soil types were infrequently and did not impact the overall speciation rate. Our findings suggest that both global temperature changes and East Asian monsoons have played crucial roles in floristic diversification within the karst ecosystems in southern China, such that speciation was higher when climate was warmer and wetter. This is the first study to directly demonstrate that past monsoon activity is positively correlated with speciation rate in East Asia. This case study could motivate further investigations to assess the impacts of past environmental changes on the origin and diversification of biodiversity in global karst ecosystems, most of which are under threat.

A new species, Gastrodia albidoides (Orchidaceae: Epidendroideae, Gastrodieae) from Yunnan, China, is described and illustrated. It is closely related to G. theana and G. albida but can be distinguished by an almost smooth perianth tube, lateral sepals fused to ½ their length, whitish and unthickened petals, a well-developed rostellum and distinct column foot.

Electrochemical profiles of Pueraria bouffordii, P. montana var. lobata, P. montana var. montana, P. montana var. thomsonii, Haymondia wallichii, Teyleria stricta and Toxicopueraria yunnanensis were recorded from leaf tissue after different solvent extractions. The voltammetric data recorded after different solvent extractions can be derived as patterns for species identification. The electrochemical behavior of plant tissue contains its electrochemical active compounds profile. As the distribution of chemical compounds in plants is controlled by genes, these profiles can reflect differences at the genetic level between species. The dendrogram deduced from the electrochemical profile has been used for polyphyly analysis. The result suggests the Teyleria stricta showed very distant relationships with other species. P. montana var. lobata, P. montana var. montana and P. montana var. thomsonii showed a close relationship because they were varietas. Interestingly, H. wallichii showed a close infrageneric relationship within these species, which disagrees with other morphological studies. In addition, the result also provides insight into phylogenetic status of the regionally Toxicopueraria yunnanensis.