Muellerella lichenicola
≡*Sphaeria lichenicola Sommerf., Suppl. Fl. Lappon.: 218 (1826). [For additional synonymy see Triebel (1989: 155)].
Description : Lichenicolous, on ascomata and upper surface of host. Perithecia globose, black, immersed in host tissues, (70–)100–125(–150) μm diam., wall 10–20(–25) μm thick, of two or more layers, inner cells colourless, outer cells brownish. Periphysoids numerous, cellular, to 15 μm long, and 1–2.5 μm thick, rarely branched. Asci clavate, thick-walled, 50–65 × 14–20 μm, with 64–100 ascospores. Ascospores ovoid to broadly ellipsoidal, pale-brown, 5–7(–8) × 2–3(–4) μm. Pycnidia immersed, to 50 μm diam., wall dark-brown. Conidia colourless, 3–3.5 × 1–1.5 μm.
S: Marlborough (White's Bay NE of Rarangi), Canterbury (Tumbledown Bay Banks Peninsula), Southland (Howell's Point). On seashore rocks. Elsewhere in its known range it is commonly found on base-rich substrata. Known also from Great Britain, Europe, Scandinavia, and North America (Triebel 1989; Alstrup & Hawksworth 1990; Triebel et al. 1991; Triebel & Scholz 2001; Hafellner et al. 2002; Zhurbenko & Laursen 2003; Triebel & Kainz 2004a).
Cosmopolitan
Hosts : Caloplaca sp. Rinodina tubulata [=Amandinea decedens](Triebel 1989: 159), R. peloleuca (Matzer et al. 1998: 183). Elsewhere in its range known also from Caloplaca arnoldii, C. flavorubescens, C. flavovirescens, C. holocarpa, C. lactea, C. saxicola, Catillaria detractula, Lecanora pulicaris, Pertusaria glomerata, Physcia stellaris, Physconia distorta, Rinodina bischoffii, P. castanomelodes, R. immersa, Solenopsora candicans, Tephromela atra, Verrucaria cf. viridula (Diederich 1986; Triebel 1989: 156).
Illustration : Triebel (1989: 157, fig. 20A).
* Muellerella lichenicola is characterised by: the lichenicolous habit; usually completely immersed perithecia, (70–)100–125(–150) μm diam.; asci with c. 100 ascospores; pale-brown, thin-walled ascospores, 5–7(–8) × 2–3(–4) μm.