Pleocatenatachiangraiensis gen. et. sp. nov. (Pleosporales, Dothideomycetes) from medicinal plants in northern Thailand.

Pleocatenata , a new genus, is introduced with its type species, Pleocatenatachiangraiensis , which was isolated from withered twigs of two medicinal plants, Clerodendrumquadriloculare (Blanco) Merr (Verbenaceae) and Tarennastellulata (Hook.f.) Ridl (Rubiaceae) in northern Thailand. The genus is characterized by mononematous, septate, brown or dark brown conidiophores, monotretic conidiogenous cells and catenate, obclavate, olivaceous to blackish brown conidia. Phylogenetic analysis of combined LSU, SSU, tef1 -α, rpb2 and ITS sequence data showed Pleocatenata forms a distinct phylogenetic lineage in Pleosporales, Dothideomycetes. Therefore, we treat Pleocatenata as Pleosporales genera incertae sedis based on morphology and phylogenetic analyses. Descriptions and illustrations of the new taxa are provided, and it is compared with morphologically similar genera.