Abstract
Hieracium sinoaestivum Sennikov sp. nov. is described as new to science and illustrated. This presumably apomictic species is solely known from two old collections made in a single locality in the Shanxi Province of China. It belongs to the hybridogenous group Hieracium sect. Aestiva (Hieracium sect. Prenanthoidea × Hieracium sect. Umbellata) and is most similar to Hieracium veresczaginii from southern Siberia. The new species occurs at low altitudes in the forest belt of Lülian Mts. and belongs to taiga forest elements.