Ceramothyrium linnaeae  

Anamorph: Conidiomata and conidiophores absent. Conidiogenous cells undifferentiated, producing conidia individually from a slightly protuberant locus. Conidia tri-, rarely tetraradiate, pale olivaceous, consisting of a ± straight main axis 25-45 µm long composed of 3-6 cells, the basal cell truncate, 3-5 µm diam., subsequent ones gradually tapered to a 2-3 µm diam. apical cell ending in a 1-1.5 µm diam. beak, thin- and smooth-walled, markedly constricted at the main septa, slightly or not so at secondary, very thin septa which sometimes divide the cells. Basal cell provided with two, rarely three opposite ± straight arms 13-30 µm long, composed of 2-3 cells with the same structure as the main axis.
Teleomorph: stroma 200-250 µm diam., consisting of a thin sheet of irregularly disposed flattened pale brown hyphae 2.5-4 µm diam., becoming more radially oriented towards the edge. Setae absent. Ascomata usually one per stroma, developing beneath the hyphal mat and pushing it up from the leaf surface, 90-120 µm diam., ± globose to broadly oblate, sometimes collapsing and becoming cupulate when dry; mid brown, thin- and smooth-walled, with a small and inconspicuous ostiole. Peridium composed of several layers of mid brown thin-walled globose cells 5-8 µm diam. Interascal tissue not seen. Asci formed in a basal fascicle,  25-32 x (10.5-) 14-15.5 µm, rather variable in shape, mostly ovoid to obpyriform, sometimes with a briefly attenuated apical section, ± sessile, thick-walled with rostrate dehiscence, with a minute apical ring ca 4 µm diam., 8-spored. Ascospores rather variable in form, measuring 12-13.5 x 3-4 µm within the ascus but extending to 19 (-24) µm after release, ovoid to fusiform-ellipsoidal within the ascus and cylindric-ellipsoidal after release, the apices mucronate, 3- (to 4-) septate, pale brown, smooth, thin-walled, hardly constricted at the septa, without a gelatinous sheath or appendages.