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 | ||
Strigula fractans P.M.McCarthy | ||
Lichenologist 29: 516 (1997). T: Lord Howe Is., Max Nicholls Track, E of Dawsons Point Ridge, 31°31'09"S, 159°03'05"E, c. 90 m, on deeply shaded basalt, 6 Feb. 1995, P.M.McCarthy 1151; holo: CANB. | ||
Thallus crustose, epilithic, determinate, continuous to irregularly and deeply rimose, pale grey-green to pale green, smooth, slightly glossy, impregated with rock fragments and crystals, 30–80 (–100) µm thick, corticate. Cortex ±prosoplectenchymatous, (10–)15–25(–30) µm thick. Algae Trentepohlia-like, in a ±clearly defined, 20–40 µm thick layer; cells broadly ellipsoidal to globose, 5–10 × 5–10 µm; interstitial mycobiont cells 2–4 (–5) µm wide. Basal layer layer absent from marginal parts of thallus, dark grey-brown to brown-black and (10–) 20–40 µm thick, but discontinuous, in older parts. Prothallus pale silvery grey or not apparent; older margins blackish and peeling. Perithecia numerous, usually solitary, 2/3 to almost entirely immersed. Apex convex plane to slightly convex, blackish, 0.1–0.15 mm diam. Involucrellum diverging from the excipulum, merging with the basal thalline layer, greyish black to brown-black in thin section, 0.18–0.28 mm diam., 25–50 µm thick at the apex, 15–30 µm thick at the base. Ostiole apical, inconspicuous or in a shallow, c. 50 µm diam. depression. Excipulum pale to medium at the base and lower sides, medium to dark brown towards the apex, 12–20 µm thick. Centrum depressed-globose, 0.12–0.18 mm diam. Subhymenium 15–20 µm deep. Paraphyses simple to sparingly branched, 1–2 µm thick. Periphyses absent or sparse, sparingly branched and 20–40 × 1 µm. Asci fissitunicate, elongate-cylindrical, 80–110 × 6–8 µm; lateral walls c. 0.7 µm thick; apex rounded, 1–2 µm thick, with a 1–2 µm broad and 1 µm tall, convex or hemispherical ocular chamber; lateral walls and apex IKI-; ascoplasma IKI+red-brown. Ascospores 8 per ascus, hyaline, elongate-ellipsoidal to elongate-fusiform, 1-septate, uniseriate or overlapping, 12–15 × 3.5–5 µm; cells similar or distal cell shorter and broader, most separating at the septum before or shortly after maturity; contents clear to guttulate. Conidiomata 90–130 µm diam., immersed, often paired or in threes, black above, colourless below. Macroconidia 1-septate, elongate-ellipsoidal to cylindrical, 6–8 × 2.5–3 µm; apices rarely with appendages c. 1 µm long and wide gelatinous appendages. Microconidia not seen. | ||
Known only from the type locality on Lord Howe Is. where it grows on deeply shaded basalt. | ||
McCarthy (1997b) |
Checklist Index |
Introduction | A–D | E–O | P–R | S–Z | Oceanic Islands | References |
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