Abstract
A new species of Lysimachia (Primulaceae), Lysimachia tianmaensis K. Liu, S.B. Zhou & Ying Wang sp. nov., is described and illustrated from Jinzhai County, Anhui, China. It is endemic to Dabieshan Mountain, China. The new species has yellow flowers and belongs to the subgenus Lysimachia section Nummularia series Grammicae. It is very easily distinguishable from other related species by having alternate leaves with brown patches beneath and an auriculated leaf base.