Abstract
Impatiens siangensis Gogoi, a new species, is described and illustrated from Arunachal Pradesh, India. The new species differs from I. marianae Hooker by the absence of white blotches on the upper leaf surface, flowers only partially purple, bracts ovate, glabrous, lateral sepals glabrous, dorsal petal glabrous, navicular, lower sepal with straight purple streaks and spur almost straight. The new species differs from I. porrecta Wallich in having stems, leaves, and floral parts glabrous, stems branched, flowers partially purple, lower sepal navicular with straight purple streaks and spur almost straight.