Pyxine subcinerea Stirt.

Data Set Maintenance: Data set compiled (from Sonoran Desert Lichen Flora). Data set author(s): Bungartz F. (02-04-26). Data set to be published after submission; February 2002.

Nomenclature: Current taxonomic status: accepted or basionymous. Taxonomic rank: species. Currently accepted name Pyxine subcinerea Stirt. Pyxine. Physciaceae Zahlbr. (1898); Lecanorineae; Lecanorales.

Type Information: Basionym: Pyxine subcinerea Stirt. Type: Pyxine subcinerea Stirt., Trans. New Zealand Inst. 30: 397 (1897).

Biogeography: Subtropical (scattered collections) and pantropical; colline and submontane. Continent: Africa, Europe (Italy and Laurimacaronesia), Northern America, Southern America, and Asia-Tropical. Checklist records: Mexico, Sonoran Desert, and United States and Canada (continental).

Ecology: Biotroph; lichenized; lignicolous or corticolous; episubstratic; growing sun-exposed or partially shaded; under conditions which are dry or moist; substrate rarely non-calciferous.

Thallus: Foliose, subdivided into main parts, lobed; lobes horizontal; subconcave or plane; separate thallus parts.3-.6 mm wide. Thallus Size and Differentiation: 3-5-(8) cm in diameter. Upper Surface: Grey-green (olivaceous) or grey-brown; pruinose; pruina abundant; whitish (often glistening); sometimes patchy; pseudocyphellate; pseudocyphellae usually isolated or reticulate (rarely), usually peripheral, submarginal (spreading on to the lobe surface); eciliate; without hairs; not isidate (never with polysidiangia); always sorediate; soralia laminal (at maturity) or subperipheral, linear (along the margin: fissural), soredia farinose; not blastidiate; not schizidiate; not lobulate. Lower Surface: Present, black or grey, black in the centre, grey (towards the lobe tips) along the margin, firmly attached attached; attached by holdfasts (true rhizines); rhizinate; rhizines abundant, black, branched, sparsely furcate.

Upper Cortex: Present; outer cortical layer paraplectenchymatous (formed by anticlinal hyphae); inner cortical layer prosoplectenchymatous (formed by periclinal hyphae). Medulla: White (very thin lower part). Lower Cortex: Present.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Apothecioid (obscurascens), orbicular, forming all across the thallus surface, soon sessile or substipitate, abundant, .3-1.5 mm in diam.. Margin: Lecideine/biatorine, smooth, excluded, distinct. Disk: Plane or weakly convex; black; epruinose. Exciple: Carbonized. Epithecium: Apical cells brownish blue (not brown: bluish black), cell pigment reacting with 10% KOH (K+ purple). Hypothecium: Brownish red (upper part of weakly developed stipe).

Asci: Dehiscence lecanoralean (lecanoral with thickened apex wall layers (apex I+ blue), with distinct axial body).

Ascospores: Dirinaria-type, c. 8 per ascus, spores 8 per ascus, ellipsoid, 13-19 µm long, 6-8 µm wide; septa present; transversally septate; wall apically thickened, subapically thickened, thickened at the septum, becoming pigmented, dark brown (at maturity) or middle brown.

Conidiomata: Present.

Conidiophores: Vobis-type VI. Conidia: Ellipsoid; 3-4 µm long; 1 µm wide.

Secondary Metabolites: Present; only in the upper part of the cortex, lichexanthone, metabolite(s) of unresolved identity: present (medulla with terpenes of a characteristic TLC pattern and an unknown pigment).

Spot Tests: Present reactions. Upper surface: K – (negative), C –, KC –, PD – cortex: KC –, –, PD – medulla: K – or + yellow changing to red (K+ purple reaction of upper part of the stipe); C –, KC –, PD – lower surface: K – soredia: K – KC –.

UV-Fluorescence: Upper thallus surface + (positive) (cortex UV+ yellow).

(report generated 13.Nov.2007)