Lysimachia caloneura G. Hao, X.L. Yu & A. Liu sp. nova (Primulaceae) is described and illustrated from Hunan, China. In general morphology it resembles the species in subgen. Lysimachia sect. Nummularia ser. Drymarifoliae, characterized by leaves with black glandular punctuations or striations, yellow corolla, filaments being longer than anthers and basally connate into a short tube, and a dorsifixed anther opening by lateral slits. Lysimachia caloneura is to some extent similar to L. patungensis, but differs from the latter by its tiny size and by having a strikingly dark green abaxial leaf surface and narrow light green bands along the main veins on the adaxial surface.