Psoroma Ach. ex Michx. (1803)

Data Set Maintenance: Data set standard item. Data set author(s): Rambold G. Data set reviewer(s): Jørgensen P. M. (98-03-20) and Scholz P. (02-05-16); revised; to be published after submission.

Nomenclature: Current taxonomic status: accepted or basionymous. Taxonomic rank: genus. Number of known taxa within this rank: 10. Psoroma. Pannariaceae Tuck. (1872); Peltigerineae; Lecanorales.

Type Information: Type: Psoroma hypnorum (Vahl) Gray.

Taxonomic Literature: Aptroot A., Diederich P., Sérusiaux E. & Sipman H.J.M.,
Biblioth. Lichenol. 64: 1-220 [150-151] (1997); Galloway D.J., Flora
of New Zealand Lichens: i-lxxiii, 1-662 [464-482], Wellington (1985);
Jørgensen P.M., Op. Bot. Soc. Bot. Lund 45: 1-123 (1978);
Jørgensen P.M. in: Nash T.H. III et al. (eds) Lichen Flora of
the Greater Sonoran Desert Region vol. 1, 431-433, Tempe (2002);
Keuck G., Biblioth. Lichenol. 6: 1-175 (1977); Purvis O.W. in: Purvis
O.W. et al. (eds), The Lichen Flora of Great Britain and Ireland,
London (1992).

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

Ecology: Biotroph; lichenized; terricolous, bryophytic, or rarely corticolous.

Lichen Photobionts: Primary photobiont present; chlorococcal. Primary photobiont taxonomy: Myrmecia? Secondary photobiont present. Secondary photobiont taxonomy: Nostoc, Nostocaceae, Nostocales, Cyanobacteria, Prokaryota.

Thallus: Crustose, not subdivided parts, squamulose. Upper Surface: Grey, green, brown, olive, and brownish yellow; special structures absent and present:; not pseudocyphellate; eciliate; without hairs; not isidate; not sorediate; not cephalodiate and cephalodiate; not lobulate; without granules granules, without thalloconidia thalloconidia. Lower Surface: Attached by the whole lower surface; special structures absent.

Reproduction Strategy: Only known as sterile, asexually reproducing form and with sexual (and possible asexual) stages. Ascocarps: Apothecioid, orbicular, forming all across the thallus surface, soon sessile. Margin: Prominent; external filaments absent. Exciple: White. Periphyses: Absent. Epithecium: Apical cells brown and brownish yellow. Interascal Hyphae: Present, scarcely branched, not or scarcely anastomosed. Hypothecium: White.

Asci: Tholus thickened, amyloid, with amyloid tube; dehiscence lecanoralean.

Ascospores: c. 8 per ascus, ellipsoid, 19-28 µm long, 8-10 µm wide, obtuse; septa absent; wall not thickened at the septum, hyaline, in Lugol's Solution negative, wall ornamented.

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

Conidia: Bacilliform; not branched; aseptate; cell wall hyaline.

Secondary Metabolites: Not detected and present (also an unidentified pigment), of the following substance class(es): dibenzofurans [and usnic acids].

(report generated 04.Okt.2007)