Abstract
Lysimachia yulongensis Z.K.Wu & Ming Y.Sheng, a new species of Primulaceae from Yunnan, China, is described and illustrated. Morphological evidence places L. yulongensis within Lysimachia sect. Pumilae, which is distinguished by dwarf plants with prostrate or nearly erect habits, few flowers clustered at the stem apex or solitary in the leaf axils near the apex, lanceolate sepals, elliptical and dorsifixed anthers and styles approximately as long as the stamens. The new species is characterised by a strongly stoloniferous growth habit, with creeping stems serving a vegetative function as stolon and terminating in leaf rosettes during fruiting; leaves that are narrowly elliptic to oblanceolate or spatulate; and flowers solitary in the leaf axils along obliquely ascending stems. Information on the distribution, phenology and conservation status of the new species is also provided.