Physconia isidiomuscigena Essl.

Data Set Maintenance: Data set authentic and standard item. Data set author(s): Esslinger T. (99-11-19). Data set not to be published after submission.

Nomenclature: Current taxonomic status: accepted or basionymous. Taxonomic rank: species. Physconia. Physciaceae Zahlbr. (1898).

Biogeography: Continent: Northern America.

Ecology: Corticolous (very rare); substrate non-calciferous (sometimes over mosses) or calciferous.

Thallus: Foliose, lobed; lobes flabellate; rounded at the front; concave; separate thallus parts (1.5)-2-4 mm wide. Thallus Size and Differentiation: Up to 11 cm in diameter; apex curved upwards. Thallus Outline: Margin crenate. Upper Surface: Grey, brown, or grey-brown; pruina abundant; usually continuous; without hairs; not isidate; sorediate; soralia grey, brown, or grey-brown, laminal, terminal (marginal or terminal and beginning on edge or undersurface of lobe), punctiform (those on the lamina), isidiate (often strongly so), soredia coarse. Lower Surface: Black in the centre, brown, white, or pale brown along the margin; rhizinate; rhizines moderately abundant, black, branched, squarrosely branched.

Upper Cortex: Outer cortical layer paraplectenchymatous. Lower Cortex: Present; prosoplectenchymatous, of periclinal hyphae.

Reproduction Strategy: Only known as sterile, asexually reproducing form (none seen).

Secondary Metabolites: Present; throughout the thallus medulla (scattered) or in soredia (or soralia), secalonic acid a or variolaric acid.

Spot Tests: Present reactions. Cortex: KC –, – (very rarely faintly yellow, but likely to be overlooked); medulla: K – or + yellow; KC –, + yellow, or + orange; soredia: K – or + deep yellow; KC – or + deep yellow (reactions sometimes obscured by dark pigments).

(report generated 13.Nov.2007)