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 | ||
Lithothelium quiescens P.M.McCarthy | ||
Australas. Lichenol. 49: 7 (2001). T: Christmas Island, The Dales, track between No. 2 and No. 3 Dales, 10°28.78'S, 105°33.44'E, alt. 40 m, on tree trunk in moderately dense primary forest, P.M.McCarthy 1478, 1.viii.2000; holo: CANB. | ||
Thallus crustose, endophloeodal to thinly epiphloeodal, inconspicuous, very thin, continuous, pale grey to pale greyish green or greenish brown, UV–. Algae Trentepohlia; cells 7–14 × 6–12 µm; interstitial hyphae 1–2 µm thick. Prothallus broad and black, or thin, or not apparent. Ascomata perithecioid, dull black, usually numerous, 1/3–2/3 immersed, usually elliptical or pyriform in outline, less commonly circular, (0.55–) 0.81(–1.1) mm wide [n = 40], solitary or 2–3 sharing a common ostiole. Centrum 0.3–0.8 mm wide. Ostiole eccentric to lateral, inconspicuous or in a concave depression that is often paler than the involucrellum and up to 100 µm diam. Ascomatal wall 50–160 µm thick, brown-black to black, becoming carbonised and brittle; surface at first smooth, becoming irregularly rugulose. Excipulum 20–35 µm thick, uniformly dark grey-brown. Paraphyses 0.7–1 µm thick, simple below, sparingly branched and anastomosing near the ostiole, not interspersed with granules or oil globules. Periphyses absent. Hymenial gel non-amyloid, Lugol's I+ orange-brown. Asci fissitunicate, (4–)8-spored, cylindrical, 100–148 × 16–25 µm; apex rounded, non-amyloid; ocular chambers of immature asci broadly tuberculate or not apparent, not sagittiform, never apparent at maturity; ascus stalk tapering. Ascospores hyaline, narrowly to broadly ellipsoid, with 3 distosepta, lacking any trace of eusepta, usually obliquely uniseriate or irregularly biseriate in the ascus, (18–)25(–31) × (10–)14(–20) µm, those in 4-spored asci not appreciably larger; apices rounded to subacute; lumina usually broadly ellipsoid or subcylindrical; apical loculi usually distinctly smaller than central loculi; endospore 2–6 µm thick; perispore not apparent. Conidiomata occasional, not numerous, 1/3–2/3 immersed, 0.08–0.12 mm diam., black above, hyaline at the base, with a simple to labyrinthine conidiogenous layer and short, unbranched conidiophores. Conidia filiform, weakly to strongly curved, 10–15 × c. 0.5 µm. | ||
Common and locally abundant on tree-trunks and thick branches in primary rainforest in Christmas Is.; endemic. | ||
McCarthy (2001j) |
Checklist Index |
Introduction | A–D | E–O | P–R | S–Z | Oceanic Islands | References |
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