


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 | ||
| Leucodecton occultum (Eschw.) Frisch | ||
| in A.Frisch, K.Kalb & M.Grube, Biblioth. Lichenol. 92: 157 (2006) Thelotrema occultum Eschw., in C.F.P. von Martius, Fl. Bras. Enum. Pl. 1(1): 174 (1833); — Leptotrema occultum (Eschw.) Hale, Smithsonian Contr. Bot. 16: 40 (1974). T: Caitété, [Bahia], Brazil, p.p.; lecto: M, fide M.E.Hale, loc. cit.; isolecto: G. Urceolaria compuncta Ach., Methodus 143 (1803), non Porina compuncta Ach., Syn. Meth. Lich. 112 (1814); Thelotrema compunctum (Ach.) Nyl., Mém. Soc. Sci. Nat. Cherbourg 5: 118 (1858); Leptotrema compunctum (Ach.) Müll.Arg., Flora 71: 527 (1888); Myriotrema compunctum (Ach.) Hale, Mycotaxon 11: 133 (1980). T: [Indonesia], C.Smith s.n.; lecto: LINN-SM 1692.7, n.v., fide M.E.Hale, Bull. Brit. Mus. (Nat. Hist.), Bot. 8: 276 (1981); isolecto: G, H-NYL 22447. Leptotrema compunctum (Ach.) Müll.Arg. var. purpuratum Müll.Arg., Bull. Soc. Roy. Bot. Belgique 30: 75 (1891). T: Costa Rica, 1890, H.Pittier, Pl. Costaric. Exs. No. 5218; holo: G; iso: US. Thelotrema loandense Vain., Cat. Welwitsch. Afr. Pl. 2(2): 429 (1901); Leptotrema loandense (Vain.) Zahlbr., Cat. Lich. Univ. 2: 636 (1923). T: Angola, F.M.J.Welwitsch 441; holo: TUR-V 26793; iso: BM. Thelotrema compunctum (Ach.) Nyl. var. antillarum Vain., Ann. Acad. Sci. Fenn., ser. A, 6(7): 134 (1915); Leptotrema compunctum (Ach.) Müll.Arg. var. antillarum (Vain.) Zahlbr., Cat. Lich. Univ. 2: 633 (1923). T: Virgin Islands, 14 Feb. 1906, C.Raunkiaer 553; holo: TUR-V 26798; iso: C. Thelotrema compunctum (Ach.) Nyl. var. praiense Vain., Bol. Soc. Brot., sér. 2, 6: 149 (1929). T: Mozambique, 1917, A.Pires de Lima 383; holo: TUR-V 34802. Thelotrema compunctum (Ach.) Nyl. f. portoricensis Vain., Mycologia 21: 38 (1929); Leptotrema compunctum (Ach.) Müll.Arg. f. portoricense (Vain.) Zahlbr., Cat. Lich. Univ. 2: 632 (1923). T: Porto Rico [Puerto Rico], B.Fink 1749; holo: W; iso: NY. | ||
| Thallus endophloeodal to epiphloeodal, to c. 500  µm thick, pale greyish to pale greenish or yellowish grey, dull to slightly glossy,  smooth or, more commonly, ±rough or porous, continuous to rugose or somewhat  verrucose, strongly rimose. Protocortex rare, discontinuous, to c. 10 µm thick.  Algal layer poorly developed, discontinuous; calcium oxalate crystals usually  abundant, scattered or clustered, generally small. Vegetative propagules not  seen. Ascomata moderately conspicuous, to c. 0.6 mm diam., ±rounded,  apothecioid, solitary, immersed to slightly emergent and hemispherical, with the  same surface features as the thallus. Disc partly visible from above, greyish,  coarsely pruinose. Pores small to moderately broad, to c. 0.2 mm diam., largely  formed by the proper exciple; proper exciple usually apically or the upper  parts becoming visible from above, ±rounded to irregular, with an entire to  indistinctly split or slightly dentate margin, whitish, occasionally shrunken,  incurved to erect, rarely somewhat recurved. Thalline rim margin broad to  gaping, thin to thick, ±rounded to slightly elongate or irregular, entire,  incurved; thalline rim concolorous with the thallus, occasionally with  concentric fissures along the ascoma outline. Proper exciple free above, thin  to thick, hyaline to pale yellowish or pale brownish internally, yellowish to  reddish brown or brownish marginally, occasionally slightly carbonised or dark brown  apically, non-amyloid. Hymenium to c. 170 µm thick, strongly conglutinated;  paraphyses ±straight, somewhat irregular and with ±distinct septation,  interwoven, parallel to sparingly branched, especially towards the margins and  the epihymenium, with slightly thickened sometimes ±irregular tips. Epihymenium  hyaline, with greyish brown granules and small crystals. Asci 8-spored,  initially with thicker lateral and apical walls; tholus absent. Ascospores submuriform  to muriform, oblong to, usually, ellipsoidal, with rounded or narrowly rounded ends,  rarely slightly subacute, becoming brown at early maturity, non-amyloid to  faintly amyloid, 20–35 (–40) × 10–17 µm, with 6–8 (–10) × 1–5 (–6) locules; locules  ±rounded to slightly angular, mostly subglobular to irregular, the end cells  having the same shape; transverse septa thin to thick, mostly regular; ascospore  wall thick, non-halonate; endospore thin. Pycnidia  not seen. CHEMISTRY: Thallus K+ orange-red, C–, P–; containing norstictic acid (major), stictic acid (minor to absent), a-acetylconstictic acid (minor to absent), connorstictic acid (minor to absent). | ||
| Common on bark in northern N.T. and north-eastern Qld; usually found in mangroves, rarely in rainforest, at altitudes to 900 m. Pantropical. | ||
| Mangold et al. (2009) | ||
| Checklist Index | 
| Introduction | A–D | E–O | P–R | S–Z | Oceanic Islands | References | 
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