Physconia leucoleiptes (Tuck.) Essl.

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 Data set author(s): Esslinger T. Data set not to be published after submission.

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

Taxonomic Literature: Esslinger, T., Mycotaxon 51: 91-99 (1994);.

Biogeography: Continent: Asia-Temperate and Northern America. Checklist records: Sonoran Desert and United States and Canada (continental).

Ecology: Corticolous; substrate non-calciferous or calciferous.

Thallus: Foliose, lobed; lobes linear; rounded (irregular) at the front; concave or usually plane; separate thallus parts 1-2 mm wide. Thallus Size and Differentiation: Up to 7 cm in diameter; apex not curved. Upper Surface: Grey, brown, or grey-brown; pruinose; pruina scarce or abundant; continuous or patchy (sometimes only on lobe ends); without hairs; not isidate; sorediate; soralia grey (or greenish-grey) or grey-brown, peripheral, terminal, labriform, sometimes isidiate, soredia usually coarse. Lower Surface: Black in the centre, white or pale brown along the margin; rhizinate; rhizines moderately abundant, black, branched, squarrosely branched.

Upper Cortex: Outer cortical layer scleroplectenchymatous. Medulla: White. Lower Cortex: Present; prosoplectenchymatous, of periclinal hyphae.

Reproduction Strategy: Only known as sterile, asexually reproducing form or with sexual (and possible asexual) stages. Ascocarps: Sparse, up to 4 mm in diam.. Margin: Lobulate.

Ascospores: 28-31 µm long, 16-18 µm wide.

Secondary Metabolites: Present; in soredia (or soralia), secalonic acid a.

Spot Tests: Present reactions. Cortex: KC –, – medulla: K – KC – soredia: K + deep yellow (younger soredia, before becoming isidioid, must be tested); KC + deep yellow (younger soredia, before becoming isidioid, must be tested) or + orange.

(report generated 13.Nov.2007)