Flora of New Zealand Series

Description : Thallus crustose, foliicolous, subcuticular, determinate, continuous, with shallow, rounded lobes separated by shallow, radiating grooves, or with concentric grooves, pale grey-green to pale-green, usually slightly glossy, to 8 mm diam., 30–60 μm thick, ecorticate. Prothallus a thin, black line delimiting adjacent or contiguous thalli. Photobiont Cephaleuros, cells rectangular to irregularly oblong, 10–20 × 6–10 μm. Perithecia very numerous, ⅔ to almost entirely immersed, usually solitary. Involucrellum apical to dimidiate, convex, jet-black, glossy, sometimes with a purplish tinge, 0.32–0.6(–0.9) mm diam., 25–50 μm thick, surface minutely wrinkled, transition from thallus usually abrupt. Ostiole inconspicuous or in a shallow depression c. 80 μm diam. Exciple 10–15 μm thick, medium- to dark-brown towards apex, colourless at lower sides and base. Centrum depressed-globose, 0.28–0.5(–0.75) mm diam. Subhymenium 10–15 μm thick. Paraphyses simple to sparingly branched, 1–2(–2.5) μm thick. Periphyses absent. Asci elongate-cylindrical, 92–110 × 6–8 μm; lateral walls c. 1 μm thick; apex rounded or subtruncate 1–3 μm thick, with a hemispherical or tuberculate ocular chamber 1–2 μm broad and 1–2 μm tall, lateral walls and apex I−, ascoplasm I+ red-brown. Ascospores 8 per ascus, colourless, elongate-ellipsoidal to elongate-fusiform, 1-septate, 13–16 × 3.5–5 μm, spore halves separating at septum early in development, 16 per ascus, uniseriate, irregularly massed, 6–8.5 × 3.5–5 μm, contents with 1–3 oil bodies. Pycnidia of two types: (1) 40–80 μm diam., immersed, glossy black above, pale- to dark-brown below, with a simple conidiogenous layer and fusiform to bacillar microconidia, 2–3 × 0.5 μm; (2) 90–170 μm diam., immersed, glossy black above, colourless below, producing macroconidia, 1-septate, elongate-ellipsoidal to cylindrical, 8–9.5 × 2–3 μm, cells with 1–3 oil bodies, apices with thread-like gelatinous appendages, 8–12(–15) μm long.

N: Northland (Church Road Scenic Reserve near Kaitaia), Wellington (Erua) S: Otago (Makarora near Haast Pass). On leaves of moderately shaded understorey shrubs or trees (Beilschmiedia tawa, Pseudowintera colorata). Known New Zealand records all from collections of the late John Bartlett (Sérusiaux 1998a: 152). Thalli generally develop near leaf wounds, perforations or marginal tears. Known also from Lord Howe I. (McCarthy et al. 1996b; Elix & McCarthy 1998; McCarthy 2003c, 2006).

Australasian

Illustrations : McCarthy et al. (1996b: 243, fig. 2); Sérusiaux (1998a: 148, fig. 4).

Strigula oceanica is characterised by: the foliicolous habit; the rounded, lobed thalli (near leaf margins and scars or tears) with radiating grooves; long, subcylindrical asci (92–100 × 6–8 μm); and ascospores, 13–16 × 3.5–5 μm separating into two halves while still in the asci.