Flora of New Zealand Series

Holotype: New Zealand. Southland, Breaksea Sound, "OG3 Island", on deeply shaded siliceous rock, 6 m, iii.1991, P.N. Johnson 5 – CHR 414089.

Description : Thallus on rocks, pale to medium olive-green, 20–50 μm thick, filmy, continuous, to sparingly cracked, matt, smooth, ecorticate, becoming gelatinous and vivid-green when moist, K−, without a prothallus. Perithecia ⅓ immersed to superficial, hemispherical to subglobose, numerous, usually solitary, occasionally paired, (0.2–)0.3(–0.36) mm diam. Apex rounded. Ostiole inconspicuous. Involucrellum black, purplish black in section, 30–50 μm thick near apex, 70–100 μm thick near the base, dimidiate or extending to exciple base level, K−, surface smooth. Exciple purple-black, 12–18 μm thick. Centrum globose to depressed-ovate, 0.12–0.18 mm diam. Paraphyses unbranched, 0.8–1.2 μm thick. Periphyses absent. Asci elongate-cylindrical with rounded or subtruncate apices, 78–90 × 7–9 μm. Ascospores 3(–7)-septate, elongate-cylindrical, elongate-fusiform or fusiform, straight, curved or faintly sigmoid, apices rounded, without a gelatinous sheath, (22–)31(–40) × (2.5–)3.5(–4.5) μm, contents clear to guttulate. Pycnidia numerous, immersed, dark-brown to black above, colourless below, 90–120 μm diam., with a non-convoluted conidiogenous layer. Conidia fusiform to bacillar, 2–3 × 0.7–1 μm.

S: Southland (Breaksea Sound Fiordland). On deeply shaded coastal rocks, growing together with P. kantvilasii (McCarthy 1993b: 95). Known only from the type locality.

Endemic

Illustration : McCarthy (1993b: 94, fig. 27).

Porina psilocarpa is characterised by: the saxicolous habit; narrow ascospores with 3 or more septa; a green, filmy thallus; and small, but prominent, smooth, black perithecia (McCarthy 1993b: 93).