Petrocosmea viridis sp. nov. of Petrocosmea (Gesneriaceae) from Guizhou, China and a supplementary and revised description of P. minor

Petrocosmea viridis M.Q. Han & Yan Liu, a new tiny but pretty species from Guizhou, China, is described and illustrated. It was found on damp cliffs in an enormous limestone sinkhole called Dadaihe Tiankeng. It is mostly similar to P. minor in its conformation of the corolla, but differs from the latter by having numerous leaves and a tiny, light green corolla. While comparing these two species, some additions and revisons of previous descriptions of P. minor had to be made.