Carbacanthographis ( Graphidaceae), a lichen genus new to Guangxi.

The lichen genus Carbacanthographis is reported as new to Guangxi, characterized by the closed disc, carbonized exciple, labia covered with a distinct white pruinose layer, warty periphysoids, and I- or weakly I+, muriform or trans-septate ascospores. The species C. marcescens is characterized by the conspicuous lirellae, the laterally carbonized exciple, the hyaline ascospores muriform with (12.5-20)×(5-7.5) μm size, and the presence of salazinic acid. The specimens examined come from Mt. Shengtang, Jinxiu, Guangxi. So far, only one species reported in the rare genus from China. The species was firstly found in the natural environment and inland of Guangxi, China. Which is very important to the flora study, protection and using of the species resource. [ABSTRACT FROM AUTHOR]