Endococcus parietinarius
≡*Microthelia parietinaria Linds., Trans. Roy. Soc. Edinb. 25: 541 (1869).
Description : Lichenicolous, parasitic on apothecia and thalli of Xanthoria parietina (forming galls on thallus, and being abundantly developed on apothecia); the fungus does not discolour the apothecia but some discolouration and gall-like growths occur on the thallus. Perithecia immersed in lower third to two-thirds, black, globose, 50–80 m diam. Asci 8-spored, 40 × 15 μm. Ascospores rather pale-brown, smooth-walled, scarcely constricted at septum, 9–13 × 4–6 μm.
N: S: St: (Cooks Arm, Port Pegasus). On Xanthoria ligulata and X. parietina from coastal rocks and inland on bark and twigs. Known also from Great Britain, Europe, Scandinavia, Greenland (Hawksworth 1982, 1985a; Roux & Triebel 1994; Alstrup 2004; Santesson et al. 2004).
Cosmopolitan
Hosts : Xanthoria ligulata, X. parietina.
Illustrations : Lindsay (1869b: pl. XXIII, fig. 33 – as Microthelia parietinaria); Hawksworth (1982: 383, fig. 4A, B, 1983a: 37, fig. 37).
* Endococcus parietinarius is characterised by: the lichenicolous habit (formation of galls on Xanthoria host); and the pale-brown ascospores not constricted at septum, 9–13 × 4–6 μm.