Thelotrema Ach. (1803)

Data Set Maintenance: Data set standard item. Data set author(s): Rambold G. Data set reviewer(s): Sipman H. (98-01-15); revised; to be published after submission.

Nomenclature: Current taxonomic status: accepted or basionymous. Taxonomic rank: genus. Number of known taxa within this rank: 100. Thelotrema. Thelotremataceae (Nyl.) Stizenb. (1862); Ostropales.

Type Information: Type: Thelotrema lepadinum (Ach.) Ach.

Taxonomic Literature: Clauzade G. & Roux C., Bull. Soc. Bot. Centre-Ouest N.S. - Numero
Special 7: 1-893 [745] (1985); Galloway D.J., Flora of New Zealand
Lichens: i-lxxiii, 1-662 [571-577], Wellington (1985); Hale M., Bull.
Br. Mus. Nat. Hist. Bot. 8: 227-332 (1981); Hawksworth D.L. in:
Purvis O.W. et al. (eds), The Lichen Flora of Great Britain and
Ireland, London (1992); Poelt J. & Vezda A., Biblioth. Lichenol.
16: 1-390 [330-332] (1981); Purvis O.W., Jørgensen P.-M. &
James P.W. in: Farkas E.+., Lücking R. & Wirth V. (eds),
Biblioth. Lichenol. 58: 335-360 (1995); Salisbury G., Lichenologist
5: 262-274 (1972).

Biogeography: Checklist records: Austria, Germany, Great Britain, Guianas, Italy, New Zealand, Sonoran Desert, Sweden and Norway, Thailand, United States and Canada (continental), and Republic of South Africa.

Ecology: Biotroph; lichenized; lignicolous or corticolous; substrate non-calciferous.

Lichen Photobionts: Primary photobiont present; trentepohlioid. Secondary photobiont absent.

Thallus: Indistinct or crustose, not subdivided parts, rimose. Upper Surface: Grey, brown, white, or brownish yellow; special structures absent or present:; not pseudocyphellate; eciliate; without hairs; not isidate; not sorediate; not cephalodiate; not lobulate; without granules or with granules granules, without thalloconidia thalloconidia. Lower Surface: Attached by the whole lower surface; special structures absent.

Medulla: Iodine reaction in Lugol's solution negative; not different with or without KOH pre-treatment (euamyloid).

Reproduction Strategy: Only known as sterile, asexually reproducing form or with sexual (and possible asexual) stages. Ascocarps: Apothecioid, orbicular, forming all across the thallus surface, not emerging, becoming adnate to soon sessile. Margin: Prominent; external filaments absent. Exciple: Brown, white, or brownish yellow. Periphyses: Absent or present. Epithecium: Apical cells black, brown, hyaline, or brownish yellow. Hymenium: Iodine reaction: Lugol’s negative, not hemiamyloid. Interascal Hyphae: Present, scarcely branched, not or scarcely anastomosed. Hypothecium: White.

Asci: Tholus thickened, not amyloid; exoascus not amyloid, not hemiamyloid.

Ascospores: 1–2 to c. 8 per ascus, fusiform or oblong, 20-160 µm long, 7-50 µm wide; septa present; transversally septate or both transversally and longitudinally, formed by the proper spore wall or endospore wall layer; wall thin, not thickened at the septum, dark brown, hyaline, or pale brown, in Lugol's Solution negative or in Lugol's Solution positive, wall not ornamented.

Conidiomata: Absent resp. not observed or present; pycnidial; formed all accross the thallus surface.

Conidiogeneous Cells: Apical. Conidia: Bacilliform.

Secondary Metabolites: Not detected or present, of the following substance class(es): ß-orcinol depsidones and (anthra-)quinones.

(report generated 04.Okt.2007)