Oxydothis Penz. & Sacc., Malpighia 11(11-12): 505 (1897)
MycoBank number: MB 3661; Index Fungorum number: IF 3661; Facesoffungi number: FoF 05091; 79 morphological species (Species Fungorum 2020), 12 species with sequence data.
Type species – Oxydothis grisea Penz. & Sacc.
Notes – Oxydothis was described from Cibodas, Java, Indonesia by Penzig & Saccardo (1897b) with three species O. grisea, O. nigricans and O. maculosa, and placed in Amphisphaeriaceae (sensu Eriksson & Hawksworth 1991). The genus is characterized by two types of ascomata, one is developed singly or in clusters, in darkened, ellipsoidal raised areas on the host surface, and have distinctive eccentric ostioles, whereas another are those developed below a raised sheet of host epidermis, and usually not darkened (Fröhlich & Hyde 2000). Hyde reviewed the taxa of Oxydothis and emphasized that ascus and ascospore morphology in this genus is consistent and reliable for distinguishing species, and also discussed the morphology of closely related genera, Ceriospora, Frondispora, Lasiobertia and Leiosphaerella (Hyde 1993b, 1994a). However, the familial classification of this genus was uncertain and it has been placed in Hyponectriaceae (Hyde 1993b) and Clypeosphaeriaceae (Kang et al. 1999b) based on morphology. Jeewon et al. (2003b) analysed DNA sequence datas and mentioned that Oxydothis was closely related to Leiosphaerella (Xylariales, genera incertae sedis), and Konta et al. (2016) placed the genus in Oxydothidaceae (Xylariales). Konta et al. (2016) also suggested that Oxydothis species may be associated with healthy plants as endophytes and become saprobes, based on their observations of appressoria. In this study, we introduce a new species, Oxydothis phoenicis, from mangrove habitats.