Australian Biological Resources Study
| Checklist of the Lichens of Australia and its Island Territories | ||
| Introduction | A–D | E–O | P–R | S–Z | Oceanic Islands | References | ||
| Pocsia mucronata P.M.McCarthy | ||
| Lichenologist 31: 141 (1999). T: Lord Howe Island, Valley of Shadows, 31°31'49"S, 159°04'40"E, alt. c. 20 m, on leaves of Howea forsteriana, 9 Feb. 1995, P.M.McCarthy 1035 & J.A.Elix; holo: CANB. | ||
| Thallus foliicolous, epicuticular, crustose, pale grey to pale grey-green, effuse or solitary, determinate and 0.3–0.6 mm wide, or coalescing to form colonies up to 10 mm wide, 15–25 µm thick, ecorticate; surface continuous, matt, ± smooth to minutely uneven. Algae trentepohlioid; cells 5–8 (–9) × 4–8 µm, sparsely distributed to densely clustered. Hyphae long-celled, 2–4 µm wide. Prothallus whitish and arachnoid or not apparent. Perithecia moderately numerous, solitary or paired on fertile thalli, becoming prominent, hemispherical to somewhat subglobose, but only slightly attenuated at the base, (0.2–) 0.26 (–0.31) mm diam., concolorous with the thallus, or with a grey-brown or orange-brown apex or uniformly orange-brown, partly to almost completely overgrown by a 20–43 (–60) µm thick layer of thallus, ± translucent when wet. Apex initially rounded, becoming slightly to deeply concave in mature and post-mature perithecia; ostiole inconspicuous or in shallow depression that often appears slightly darker than the surrounding tissues. Involucrellum absent. Excipulum hyaline to pale orange-brown, 25–40 µm thick at the sides and towards the apex, and composed of rounded to polygonal, thin-walled, 6–12 µm wide cells; 12–20 µm thick at the base and composed of elongate, periclinal, more thick-walled, 13–19 × 4–7 µm cells. Centrum subglobose to depressed-ovate, 0.14–0.19 mm diam. Subhymenium 10–20 µm thick. Hymenial gel Lugol's I-. Paraphyses absent or sparse and simple in immature perithecia, then absent at maturity. Periphyses simple to sparingly branched, 15–24 × 2–3 µm. Asci fissitunicate, 8-spored, broadly to elongate-ellipsoid, occasionally broadly clavate, 62–80 × 16–26 µm; ascoplasma Lugol's I+ dark red-brown; ascus wall 2–3 µm thick at the sides, 3–5 µm thick at the apex, with or without a broad and rather flat ocular chamber, I-. Ascospores colourless, (7–) 11–13 (–15)-septate, fusiform-cylindrical, usually slightly curved, occasionally straight or faintly sigmoid, tapering slightly to rounded apices or with an acuminate proximal apex, massed in the ascus, (39–) 53 (–68) × (4–) 5 (–6.5) µm; wall c. 0.7 µm thick; perispore absent; septa thin; apical cells with a blunt or pointed, (0.7–) 1 (–1.5) µm long mucro; contents minutely granulose or sparsely guttulate. Conidiomata convex, 70–120 µm diam., with a thalline margin, a 30–70 µm diam. pinkish grey apex and a simple conidiogenous layer. Conidia simple, curved-acicular, 40–52 × 2 µm. | ||
| Known from leaves in two shaded and comparatively dry sites in lowland subtropical forest in Lord Howe Is.; also in Christmas Is. | ||
| McCarthy (1999) | ||
| Checklist Index |
| Introduction | A–D | E–O | P–R | S–Z | Oceanic Islands | References |
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