The rediscovery of Impatiens sigmoidea Hook. f. (Balsaminaceae) in Guizhou, China after more than 100 years

Impatiens sigmoidea was described in 1908 by the eminent British plant taxonomist J. D. Hooker based on specimens collected by the French missionaries E. M. Bodinier et al. from Guizhou, China. However, there has been no other records since then. After years of concern, we rediscovered I. sigmoidea in one of its type localities, Gao-po Town, in 2018. A revised description, colour photographs and a provisional IUCN Red List assessment of this species are provided, along with discussions of its geographical distribution, ecology and morphological comparison with I. lasiophyton. The lectotype of I. sigmoidea is also designated here. The rediscovery provides an essential basis for enriching the botanical resources of the genus Impatiens.