Impatiens longiaristata (Balsaminaceae), a new species from western Sichuan Province in China, is described and illustrated here based on morphological and molecular data. It is similar to I. longiloba and I. siculifer, but differs in its lower sepal with a long arista at the apex of the mouth, spur curved downward or circinate, and lower petal that is oblong-elliptic and two times longer than the upper petal. Molecular analysis confirmed its placement in sect. Racemosae. Simultaneously, during the inspection of the protologues and type specimens of allied species, it was found that the types of two names from this section were syntypes based on Article 9.6 of the International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code). According to Articles 8.1, 9.3, and Recommendations 9A.1, 9A.2, and 9A.3, the lectotypes of these two names are here designated.
Keywords: Sichuan; lectotype; new taxa; phylogeny; protologue; taxonomy.