Orthobellus A.A. Silva & Cavalc., in Silva, Cavalcante & Leal, Publicações Inst. Micol. Recife 691: 4 (1973).
Parasitic on lower surface of living leaves. Sexual morph: Ascomata superficial, seated on a subiculum, solitary to gregarious, globose to subglobose, with apical pore, surrounded by brown mycelium. Peridium comprising multi-layers of brown to dark brown cells of textura angularis, inner layers compressed, lacking pseudoparaphyses. Asci 8-spored, bitunicate, cylindrical to subclavate, sessile, slightly curved, apex rounded. Ascospores fasciculate, cylindrical fusiform, straight to slightly curved, multi-septate, not constricted at the septa, hyaline to pale brown, smooth-walled. Asexual morph: Unknown (adapted from Phookamsak et al. 2016).
Type species: Orthobellus leguminosarum A.A. Silva & Cavalc.
Notes: Orthobellus resembles other genera in Schizothyriaceae in having membranous ascomata, and lacking ostioles, but the genus differs from other species in having narrowly anastomosing pseudoparaphyses and a developed peridium at the base. Phookamsak et al. (2016) transferred Orthobellus from Schizothyriaceae to Dothideomycetes, genera incertae sedis based on morphology such as narrow anastomosing pseudoparaphyses and a developed peridium at the base. Doilom et al. (2018) transferred Orthobellus to Johansoniaceae based on morphological resemblance to Johansonia such as membranous ascomata lacking ostiole, barely anastomosing, pseudoparaphyses thin-walled at the base and hyaline, ovoid to ellipsoidal,uniseptate ascospores with an apical cell wider than basal cell. Orthobellus differs from Johansonia in having short, brown, aseptate hyphae at the base of ascomata, and clavate asci. More collections with DNA sequence data are needed to confirm the placement of Orthobellus within Johansoniaceae.