Physcia (Schreb.) Michx. (1803)

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

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: genus. Number of known taxa within this rank: 70. Physcia. Physciaceae Zahlbr. (1898); Lecanorineae; Lecanorales.

Type Information: Type: Physcia tenella (Scop.) DC.

Taxonomic Literature: Coppins B.J. in: Purvis O.W., Coppins B.J., Hawksworth D.L., James
P.W. & Moore D.M. (eds), The lichen flora of Great Britain and
Ireland: 1-710 [467-470] (1992); Galloway D.J., Flora of New Zealand.
Lichens: 1-662 [391-395] (1985); Hafellner J., Mayrhofer H., Poelt
J., Herzogia 5: 39-79 (1979); Kashiwadani H., Ginkgoana 3: 1-77
(1975); Maas Geesteranus R.A., Blumea 7: 206-287 (1952); Moberg R.,
Symb. Bot. Upsal. 22(1): 1-108 (1977); Moberg R., Nord. J. Bot. 6:
843-864 (1986); Moberg R., Nord. J. Bot. 10: 319-342 (1990); Moberg
R. in: Nash T.H. III et al. (eds) Lichen Flora of the Greater Sonoran
Desert Region vol. 1, 358-373, Tempe (2002); Poelt J., Khumbu Himal,
Ergebn. Forsch.-Unternehmen Nepal Himalaya 6(2): 57-100 (1974);
Rambold G. & Triebel D., Biblioth. Lichenol. 48: 1-201 [116]
(1992); Thomson J.W., Beih. Nova Hedwigia 7: 1-172 (1963).

Biogeography: Checklist records: Austria, Bolivia, 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 or lichenicolous; bryophytic, lignicolous, or corticolous; substrate non-calciferous or calciferous.

Lichen Photobionts: Primary photobiont present; chlorococcal. Primary photobiont taxonomy: Trebouxia (A. Beck 22-05-97); Trebouxiaceae; Trebouxiales, Trebouxiophyceae, Eukariota. Secondary photobiont absent.

Thallus: Foliose, not subdivided parts, lobed. Thallus Outline: Soon disappearing. Upper Surface: Grey, white, olive, or brownish yellow; special structures absent or present:; not pseudocyphellate; eciliate or ciliate; without hairs; not isidate or isidiate; not sorediate or sorediate; not cephalodiate; not lobulate; without granules granules, without thalloconidia thalloconidia. Lower Surface: Attached by holdfasts; special structures present:; not pseudocyphellate; not cyphellate; rhizinate; without thalloconidia thalloconidia; not cavernulate; not tomentose.

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, soon sessile to substipitate. Margin: Prominent; external filaments absent. Exciple: White or brownish yellow. Periphyses: Absent. Epithecium: Apical cells brown or brownish yellow. Interascal Hyphae: Present, scarcely branched, not or scarcely anastomosed. Hypothecium: White or brownish yellow.

Asci: Tholus thickened, amyloid, with non-amyloid wide axial body and divergent amyloid flanks towards apex; dehiscence lecanoralean.

Ascospores: c. 8 per ascus, broadly ellipsoid or ellipsoid, 13-28-(32) µm long, 6-13-(16) µm wide, obtuse; septa present; transversally septate, 1-transversally septate; wall thin, thickened at the septum, dark brown, in Lugol's Solution negative, wall not ornamented.

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

Conidiogeneous Cells: Intercalar. Conidia: Bacilliform; aseptate; cell wall hyaline.

Secondary Metabolites: Present, of the following substance class(es): ß-orcinol depsides and (tri-)terpenoids.

(report generated 04.Okt.2007)