Five new synonyms in Impatiens (Ericales, Balsaminaceae) from China

Species of Impatiens L. on the Yunnan-Guizhou Plateau show exceptionally high diversity, but inadequate early regional surveys have led to persistent taxonomic ambiguity. Critical study of the type and additional specimens, supported by field observations and comparative morphology, demonstrates that: (1) Impatiens lepida Hook.f. is conspecific with Impatiens piufanensis Hook.f.; (2) Impatiens sigmoidea Hook.f. and Impatiens martinii Hook.f. represent a single species; (3) Impatiens abbatis Hook.f. and Impatiens leveillei Hook.f. are not distinct from Impatiens arguta Hook.f. & Thomson; (4) Impatiens foetens Hook.f. ex H. Lév. and Impatiens cyanantha Hook.f. are considered conspecific. In accordance with the International Code of Nomenclature for algae, fungi, and plants (Madrid Code 2025), the above names are reduced to synonymy, and lectotypes are here designated for I. martinii and additional species to ensure nomenclatural stability.