Impatiens bijieensis (Balsaminaceae), a new species from karst plateau in Guizhou, China

Impatiens bijieensis X.X. Bai & L.Y. Ren, sp. nov. from northwest Guizhou Province, China, is described and illustrated. This new species is distributed discontinuously in Jiulongshan, Dafang County and Dajiucaiping, Hezhang County, both of which are in the Wumeng Mountain area, a karst plateau landform. The new species is morphologically similar to I. pterosepala Hook.f., I. lasiophyton Hook.f. and I. leptocaulon Hook.f. in height and flower shape and it especially resembles I. lasiophyton in pilosity. However, it differs in its deep purplish-red flower, 2-lobed lower sepal apex and cylindrical capsule. A detailed description, colour photographs and a provisional IUCN Red List assessment are provided along with discussions of its geographical distribution, ecology and morphological relationships with other similar species.