Impatiens mogangensis (Balsaminaceae), a new species from Yunnan, China

Impatiens mogangensis, a new species discovered in the limestone region of southeast Yunnan, China, is described and illustrated. Based on characteristics such as extremely contracted pedicels, connate lateral united petals, and four-locular ovary, this species is classified within Impatiens sect. Semeiocardium. Within the section, I. mogangensis resembles I. morsei morphologically in the white-tipped, yellow and brown-striated flowers, obconic capsule, and brick-shaped seeds. Additionally, I. mogangensis is similar to I. bonii in their reflexed lower lobes of lateral united petals, obconic capsules, and brick-shaped seeds, but can be distinguished from I. morsei and I. bonii by having 5–7 pairs of lateral leaf veins, serrate leaf margins, and falcate lower lobes of the lateral united petals. Besides, I. mogangensis is confined to the limestone region in Mogang village of south-eastern Yunnan and does not overlap with the distribution of I. morsei and I. bonii. In conclusion, the new species we proposed is a morphological transitional type between I. morsei and I. bonii respectively with their endemic geographical distributions.