Flora of New Zealand Series

Holotype: New Zealand. Near Orewa 30 km N of Auckland, in coastal forest on dead leaves of Beilschmiedia tawa, 14.xi.1979, J.K. Bartlett s.n. – LG. Isotypes – CHR, Herb. Aptroot.

Description : Thallus epiphyllous, subcuticular, not growing along the nerves, margins or scars of leaves, ±circular, 2.5–3.5 mm diam., c. 25–40 μm thick; quite abundant, whitish grey to greyish green, shiny, with smooth surface and marginal rounded lobes, c. 0.2 mm wide, or with tiny juxtaposed lobes; margins with a discontinuous or continuous black line and usually with numerous, rather regularly scattered, small (c. 50 μm diam.) black papillae on thallus surface when thallus is of juxtaposed, contiguous lobes; thallus hyphae spreading radially just under leaf cuticle, 1.5–2.0 μm wide near margins where they laterally anastomose to form a reticulum covering photobiont plate. Photobiont forming a regular plate beneath thallus hyphae, pale-green to yellowish green, of irregular or rectangular cells ±radiately arranged, 8–18 × 4–5 μm, several ±globose cells, c. 10–12 μm diam. usually present, ? Cephaleuros. Perithecia, single, 0.1–0.15(–0.2) mm diam. and 70–100 μm thick, or aggregated into groups of 2–8, positioned centrally, hemispherical to ±applanate, apices rounded or slightly conic, ostiole black, shining, slightly depressed. Hamathecium hyaline I−, composed of branched and slightly anastomosed, septate pseudoparaphyses. Asci bitunicate, clavate or with inflated base I−, 40–50(–55) × 10–12(–15) μm, wall c. 4 μm thick at top, with a narrow, distinct ocular chamber. Ascospores ellipsoidal with rounded ends, dark-brown, slightly constricted at septum, proximal cell smaller and more elongate than distal one. Pycnidia not seen.

N: North Auckland (Orewa), Auckland. On dead leaves of Beilschmiedia tawa in coastal forest. Still very poorly collected and understood.

Endemic

Illustrations : Sérusiaux & Aptroot (1998: 144. fig. 1; 145, figs 2,3).

Mycomicrothelia striguloides resembles species of Strigula in the subtilissima- group, but the brown, 1-septate spores, ascomata structure, hamathecium and asci are consistent with its placing in Mycomicrothelia.