Porina leptalea
≡Biatora leptalea Durieu & Mont., Fl. d'Algér. Crypt. 1: 268 (1849).
Description : Thallus epiphloeodal or epilithic, filmy to granulose, continuous to sparingly rimose, greyish green or pale to dark olive-green, matt, ±smooth to minutely uneven, c. 15–30 µm thick, ecorticate; prothallus not apparent. Photobiont Trentepohlia; cells 7–14 × 6–12 µm. Perithecia almost superficial, hemispherical to subglobose, 0.14–0.24(–0.28) mm diam., dull orange-brown to red-brown; apex rounded or somewhat flattened; ostiole inconspicuous. Involucrellum contiguous with the exciple, sometimes incurved beneath, 25–40 µm thick, containing algae or covered by a thin layer of thallus, K−. Exciple c. 15 µm thick, hyaline to pale orange-brown. Centrum 0.1–0.2 mm wide. Asci cylindrical-clavate or narrowly obclavate, 70–100 × 7–11 µm. Ascospores fusiform, fusiform-cylindrical or oblong, 3-septate, 15–25 × 2–4(–5) µm; perispore not apparent. Pycnidia ±hemispherical, 0.09–0.12 mm diam., orange-brown to reddish brown. Conidia ellipsoidal to bacillar, 1.5–2.5 × 0.7 µm.
N: Wellington (Titahi Bay). S: Otago (Bethune's Gully, Broad Bay, Maungatua). On shaded, streamside rocks, coastal rocks, and rocks in grassland. Known also from Great Britain, Europe, North America, Brazil, Christmas I., Australia, Taiwan (Kantvilas & James 1991; Purvis & James 1992e; Nimis 1993; Diederich & Sérusiaux 2000; Scholz 2000; Hafellner & Türk 2001; McCarthy 2001l, 2003c, 2006; Aptroot 2002e, 2003a) and the subantarctic Marion and Prince Edward Is (Øvstedal & Gremmen 2001). A detailed geographical distribution of this species is given in McCarthy (2003d: 58–59).
Cosmopolitan
Illustrations : Swinscow (1962: 39, fig. 9); Dobson (2000: 317; 2005: 358).
Porina leptalea is characterised by: the saxicolous habit; the effuse, grey-green, very thin thallus; reddish brown, hemispherical perithecia; simple paraphyses; and hyaline, 3-septate ascospores, 15–25 × 2–5 μm.
