<i>Petrocodon gracilis</i> (Gesneriaceae), a New Species From Southwestern Guangxi, China

The genus <i>Petrocodon</i> is renowned for its remarkably diverse floral morphology, exhibiting a high level of disparity compared to most genera within Gesneriaceae. In this study, we present a detailed description and illustration of <i>Petrocodon gracilis</i> T. Ding & B. Pan, a new species with unique floral features that is native to Guangxi, China. This species is geographically close to <i>P. jingxiensis</i> H.S. Gao & W.B. Xu and is indistinguishable from <i>P. jingxiensis</i> in vegetative characteristics. However, it can be clearly distinguished from the latter by its shorter pedicels, slender tubular corolla, shorter corolla tube, distinctly unequal corolla lobes with upper ones linear and reflexed and lower ones oblanceolate, and included chiritoid-like stigma. The presence of linear upper lobes and the chiritoid-like stigma has not been previously reported in <i>Petrocodon,</i> and the emergence of this new species will further expand the morphospace occupied by this morphologically diverse genus.