Justicia tiandengensis (Acanthaceae), a new species from Guangxi, China

Justicia tiandengensis (Acanthaceae), a new species from a karst cave in southwestern Guangxi, China, is described and illustrated based on morphological and molecular evidence. This new species resembles Justicia leptostachya Hemsl. in having elongated stems, cauline leaves, and more than one flower per rachis node, but it can be readily distinguished by its oblong, thickly papery leaf blades (vs. ovate, thinly papery); calyx 2–3 mm long (vs. ca. 6 mm long); and pubescent ovary and style (vs. glabrous).

Photographs, an illustration, and a distribution map are also provided.