Pyxine pyxinoides (Müll. Arg.) Kalb

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. Taxonomic rank: species. Currently accepted name Pyxine pyxinoides (Müll. Arg.) Kalb. Pyxine. Synonyms: Pyxine minuta Vain.
Pyxine brachyloba Müll. Arg.; Physciaceae Zahlbr. (1898); Lecanorineae; Lecanorales.

Type Information: Basionym: Catolechia pyxinoides Müll. Arg. Type: Pyxine pyxinoides (Müll. Arg.) Kalb.

Biogeography: Neotropical; montane. Continent: Northern America and Southern America. Checklist records: Mexico and Sonoran Desert.

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

Thallus: Foliose, subdivided into main parts, lobed; lobes horizontal; rarely subconcave or plane; separate thallus parts.2-.3 mm wide. Thallus Size and Differentiation: Up to 6 cm in diameter. Upper Surface: Grey-brown (to olivaceous in older thalli); pruinose (hardly visible); pruina scarce; whitish; sparsely pseudocyphellate; pseudocyphellae usually isolated or reticulate (rarely), usually peripheral, submarginal or usually marginal; eciliate; without hairs; not isidate; not sorediate; not blastidiate; not schizidiate; not lobulate. Lower Surface: Present, black or grey (towards lobe tips), black in the centre, grey along the margin, firmly attached attached; attached by holdfasts (true rhizines); rhizinate; rhizines sparse, black, branched, sparsely furcate; not sorediate; not tomentose.

Upper Cortex: Present; outer cortical layer paraplectenchymatous (formed by anticlinal hyphae); inner cortical layer prosoplectenchymatous (formed by periclinal hyphae). Medulla: Yellow (light orange upper part or white throughout) or white. Lower Cortex: Present.

Reproduction Strategy: Often with sexual (and possible asexual) stages. Ascocarps: Apothecioid (obscurascens-type), forming all across the thallus surface, soon sessile or substipitate, .25-.6 mm in diam.. Margin: Lecideine/biatorine (throughout development), persistent, distinct. Disk: Plane; black; epruinose. Exciple: Carbonized (throughout development). Epithecium: Apical cells brownish blue (not brown, bluish black), cell pigment reacting with 10% KOH (K+ purple). Hypothecium: White (lower part of indistinct stipe) or lemon (citrine) (upper part of indistinct stipestipe).

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

Ascospores: Dirinaria-type, c. 8 per ascus, spores 8 per ascus, ellipsoid, 13-17 µm long, 4-7 µm wide; septa present; transversally septate; 1-transversally septate; wall apically thickened, subapically not thickened, thickened at the septum, becoming pigmented, dark brown (at maturity) or middle brown.

Conidiomata: Present.

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

Secondary Metabolites: Present; throughout the thallus medulla (testacein), lichexanthone (and testacein (in all Sonoran collections)), metabolite(s) of unresolved identity: present (terpenes of characteristical TLC-array in the medulla, Sonoran material always with testacein).

Spot Tests: Absent or present (in medulla of all Sonoran Specimen because of testacein) reactions. Upper surface: K – (negative), C –, KC –, PD – cortex: KC – (upper and lower cortex), – (upper and lower cortex), PD – (upper and lower cortex); medulla: K – (upper and lower medulla); C – (upper and lower medulla), KC – (upper and lower medulla), PD – (upper and lower medulla: in some non-Sonoran specimens without testacein); lower surface: K –.

UV-Fluorescence: Upper thallus surface + (positive) (because of lichexanthone).

(report generated 13.Nov.2007)