L.N. Vassilyeva (2000): “Hysterothecia aggregated, linear, elongated, curved or flexuous, black, fragile, smooth. Asci clavate or cylindrical, 8-spored, short-stipitate. Ascospores fusiform or slightly clavate, with a septum in the middle, coloured. This genus is similar to Actidium (Mytilinidiaceae) in coloured 2-celled ascospores, but it’s hysterothecia are not conchiform & are similar to those in Glonium (Hysteriaceae). Type species: Actidiographium orientale L.N. Vassilyeva. Monotypic. Hysterothecia densely aggregated, linear, elongated, curved or flexuous, black, smooth, about 1.5 – 2 mm in length. Asci clavate or cylindrical, 40 – 50 x 4 – 6 um, short-stipitate. Ascospores fusiform or slightly clavate, with a septum in the middle, brownish, 13.2 – 16.5 x 3 – 4 um. Distribution: Russia, Primorsky Territory, Anisimovka, on bark of coniferous tree, collected 01 09 1993.”