Abstract
A new species, Thyronectria berberidis, is described and illustrated based on collections on Berberis heteropoda from the Ili area of Xinjiang Uygur Autonomous Region in China. Thyronectria berberidis is characterized by superficial, gregarious ascomata that become cupulate upon drying, with (1–6)7-septate, ellipsoidal to fusiform ascospores. In addition, T. lamyi is reported for the first time in China. The morphology characteristics of T. berberidis and T. lamyi were compared to those of close relatives. Their phylogenetic positions were confirmed by analyses of combined sequences of alpha-actin, the internal transcribed spacer, the large nuclear ribosomal RNA subunit, translation elongation factor 1-alpha and beta-tubulin. This is the first record that Thyronectria is established in the B. heteropoda in China.