Porina speciosa
Holotype: New Zealand. South I., Nelson, Brook Stream Track, 41º10.1S, 173º17.6'E, 130 m, on siliceous rock, 22.x.1995, W.M. Malcolm 2487 – CHR 502688. Isotype – Herb. W. Malcolm.
Description : Thallus crustose, pale-green, continuous to sparingly rimose, tending to peel from substratum, slightly glossy, smooth to minutely wrinkled, 25–50 μm thick, saxicolous, without a prothallus. Perithecia numerous, hemispherical to subglobose, (0.5–) 0.8(–1) mm diam., partly or almost entirely overgrown by a thalline layer 10–25 μm thick. Apex initially with a shallow depression 40–80(–100) μm wide, becoming rounded or somewhat flattened; ostiole inconspicuous, concolorous with thallus or slightly paler. Involucrellum orange-brown, extending to exciple base level, K+ dark-orange, 60–100 μm thick, containing numerous photobiont cells. Exciple 20–30 μm thick, hyaline to pale orange-brown, K+ medium-orange. Centrum subglobose to depressed-ovate, 0.38–0.6 mm diam. Periphyses 10–20 μm long, to 1 μm thick. Paraphyses simple, 1–1.5 μm thick. Asci elongate-ellipsoidal to cylindrical, with rounded apices, 240–295 × 40–52 μm, without an apical, chitinoid ring. Ascospores (7–)9(–13)-septate, straight, curved or subsigmoid, with a persistent gelatinous sheath 4–8(–10) μm thick, (65–)95(–125) × 15–18(–22) μm (excluding sheath), central 2–4 cells usually larger than those at apices. Pycnidia not seen.
S: Nelson. Known only from the type locality. In lowland coastal forest, associating with the lichens Pannaria immixta, Porina geuntheri, P. partita and species of Leptogium.
Endemic
Illustrations : McCarthy & Malcolm (1996a: 545, fig. 1; 546, fig. 2).
Porina speciosa is characterised by: the saxicolous habit; its large perithecia with orange-brown involucrellum; and exceptionally large, multiseptate ascospores with a thick, persistent, gelatinous sheath.