Hysterium angustatum Alb. & Schw. ex. Mér.
Hysterium pulicare var. angustatum Fr.
Unlichenized Ascomycota potentially confused with resembling lichens (Graphina, Graphis, ...)
Thallus absent. Fruiting bodies consisting of blackish hysterotheca, charcoal-like aspect, tightly appressed to the substratum, either isolate or clustered, 0.5-1.5 x 0.3-0.8 mm, straight or slightly bent, ellipsoid with a central split showing the dark brown hymenium, edged by parallel ribs. Ascii cylindrical, 60-120 x 8-14 µm with one tip rounded. Ascospores brown-blackish, ellipsoid, straight or slightly curved with apex rounded, 3-septate, 17-25 x 6-8 µm. Found on barks, notably dead branches of deciduous trees. See Hysterium pulicare of which the ascospores are larger with tips paler.*