Sclerophyton californicum (Tuck.) Hasse

Data Set Maintenance: Data set authentic and standard item. Data set author(s): Egea J. M. & Torrente P. (00.03.23). Data set not to be published after submission.

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: species. Sclerophyton. Synonyms: Chiodecton californicum Tuck.; genus of unknown placement (incertae sedis) (Roccellaceae Chevall 1826); Arthoniales.

Taxonomic Literature: Egea J.M. & Torrente P., The Briologist 98: 207-217 (1995).

Biogeography: Continent: Northern America. Checklist records: Sonoran Desert.

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

Lichen Photobionts: Primary photobiont present, trentepohlioid.

Thallus: Crustose, not subdivided parts, rimose or areolate (primarily areolate); separate thallus parts thick. Thallus Outline: Often persistent. Upper Surface: White (creamy) or grey-green, smooth or rough; special structures absent; epruinose; without hairs; not sorediate, soralia isolated, not confluent with other soralia.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Apothecioid, orbicular or linear, forming independently from the host thallus or mycelium, not emerging, soon sessile, slightly constricted at the base, abundant, pseudostromatic, .4-1.2 mm in diam.. Margin: Crenulate, smooth, persistent, distinct or prominent, pale green or pale brown, epruinose or slightly pruinose; with surface structures surface structures; external filaments absent. Disk: Plane, black, not exposed or fully exposed, pruinose, pruina scarce, white. Exciple: Carbonized, black or brownish red. Amphithecium (thalline excipulum): Photobiont abundant. Amphithecial Cortex: Present, distinctly developed. Episamma: Without episamma. Epithecium: With epithecium; apical cells not swollen or slightly swollen, brown. Hymenium: 140-160 µm high, white, iodine reaction: Lugol’s negative, hemiamyloid. Interascal Hyphae: Present, distinctly branched, distinctly anastomosed; cells 1.5 µm wide. Hypothecium: Black or brownish red, pigment homogenously distributed throughout.

Asci: Clavate or narrowly clavate, indistinctly stipitate, 56-70 µm long, 16-19 µm wide; tholus thickened, amyloid, hemiamyloid, in Lugol's Solution + dark blue, with amyloid tube; dehiscence bitunicate; endoascus hemiamyloid throughout.

Ascospores: c. 8 per ascus, ellipsoid or fusiform, 22-30-(32) µm long, 5-8-(9) µm wide, obtuse; septa present, (3)-5-7-transversally septate; wall thick, distinctly differentiated into primary and secondary wall, laterally constricted where the septum meets the spore wall, becoming pigmented, dark brown or hyaline, not ornamented, distinctly halonate, i.e., with a thick mucilaginous sheath.

Conidiomata: Present, pycnidial, sparse, immersed or adnate.

Pycnidia: Pyriform, unilocular. Conidia: Filiform or curved; microconidial, 18-25 µm long, 1 µm wide; aseptate.

Secondary Metabolites: Present, erythrin or lecanoric acid.

Spot Tests: Present reactions. Upper surface: K – (negative) or + deep yellow, C + red, KC –, PD –.

(report generated 04.Okt.2007)