Flora of New Zealand Series

Holotype: New Zealand. Otago, Old Man Ra., near Prophet's Rock, tributary of Omeo Creek, 1020 m, on schist in a mountain stream, 21.v.1993, P.N. Johnson 660a. – CHR 494627. Isotype – MEL.

Description : Thallus crustose, epilithic, mid-brown, matt, ±smooth, continuous to sparingly rimose, becoming gelatinous and dark khaki-brown when moist, 40–140 μm thick, over a brown to black basal layer, 50–120 μm thick. Prothallus not apparent, or visible as a pale, discontinuous marginal zone or as dark grey-brown lines separating contiguous thalli. Perithecia very numerous, almost entirely immersed in thallus or, less commonly, in thalline verrucae; at most only the upper part of the involucrellum and the ostiole exposed. Perithecial apex plane to subconvex. Ostiole inconspicuous or in a shallow depression, 40–100 μm. Involucrellum brown-black, ±contiguous with exciple, extending to exciple-base level and merging with basal layer of thallus, 0.18–0.3 mm diam., (30–)60(–100) μm thick near apex, 30–70 μm thick at the base. Centrum subglobose. 0.12–0.18 mm diam. Exciple hyaline to brown at base and sides, brown to brown-black towards apex, c. 20 μm thick. Periphyses 20–30 × 1.5–2 μm, simple to sparingly branched. Hymenial gel I+ red-brown. Asci clavate to cylindrical-clavate 75–100 × 20–24 μm. Ascospores ellipsoidal to elongate-ellipsoidal, 18–35 × 8–14 μm, contents finely or coarsely granular-guttulate.

S: Southland (S Mavora Lake, Garvie Mts), Otago (Dart Valley, Old Man Ra., Rock & Pillar Ra.). On schist, stones, rocks and boulders in streambeds and at edges of streams and lakes.

Endemic

Illustrations : McCarthy & Johnson (1995: 503, fig. 2); Johnson & McCarthy (1997: 15, fig. 3); Malcolm & Galloway (1997: 180); Malcolm & Malcolm (2000: 79).

Verrucaria austroschisticola is characterised by: the saxicolous (aquatic rocks) habit; the dark, often thick thallus; small immersed perithecia; and large ascospores.