Porina corrugata
Description : Thallus endolithic to epilithic or epiphloeodal, rimose to areolate, greenish white, pale-grey or pale or medium grey-green, matt, smooth, 50–150(–250) µm thick, ecorticate; prothallus not apparent. Photobiont Trentepohlia; cells 7–23 × 7–17 µm. Perithecia superficial, subglobose to globose, 0.4–0.8(–1.4) mm diam., often overgrown almost to the apex by a thalline layer with a rugose to verrucose surface; apex plane or rounded, dark-grey to black; ostiole inconspicuous or in a shallow depression. Involucrellum dark-brown, grey-black or black, extending from the apex to the base of the perithecium as a K+ reddish brown layer, 20–40 µm thick, subtended by fungal hyphae, algal cells and crystals. Exciple 20–30 µm thick, hyaline to pale yellow-brown. Centrum 0.18–0.55 mm wide. Asci elongate-cylindrical, 103–141 × 7–10 µm. Ascospores fusiform to narrowly ellipsoidal, 3-septate, 19–23 × 3–6 µm; perispore thin or not apparent. Pycnidia semi-immersed to almost completely immersed, 60–180 µm diam. Conidia narrowly ellipsoidal, bacillar to fusiform, 2.5–4 × 1–2 µm.
S: Marlborough (Kaikoura). On limestone cliff. Associating with species of Caloplaca. Known also from Australia and South Africa (McCarthy 2003c, 2003d, 2006).
Western Pacific
Illustration : McCarthy (1993b: 38, fig. 6).
Porina corrugata is characterised by: the saxicolous, basicolous (limestone) habit; globose, superficial perithecia, overlain by a wrinkled to verrucose thalline layer; a colourless to pale yellow-brown exciple; and 3-septate ascospores, 19–23 × 3– 6 µm.
