Sclerophyton cerebriforme Egea & Torrente

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 Data set not to be published after submission.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: basionymous or accepted. Taxonomic rank: species. Sclerophyton. 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, episubstratic; growing partially shaded or fully shaded, under conditions which are 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 or grey-green, smooth; special structures absent; epruinose; without hairs; not sorediate, soralia isolated, not confluent with other soralia.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Perithecioid, linear, forming independently from the host thallus or mycelium, not emerging, abundant, pseudostromatic. Margin: Smooth, persistent, distinct or indistinct, black, distinctly pruinose; with surface structures surface structures; external filaments absent. Disk: Plane, black, not exposed, pruinose, pruina white. Exciple: Carbonized, black or brownish red. Amphithecium (thalline excipulum): Photobiont absent. Amphithecial Cortex: Absent. Episamma: Without episamma. Epithecium: With epithecium; apical cells not swollen or slightly swollen, brown. Hymenium: 300-350 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: Narrowly clavate, indistinctly stipitate, 125-160 µm long, 25-30 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, fusiform, 30-40 µm long, 8-12 µm wide, obtuse; septa present, 6-9-(10)-transversally septate; wall thick, distinctly differentiated into primary and secondary wall, not constricted where the septum meets the spore wall, becoming pigmented, middle brown or hyaline, not ornamented, distinctly halonate, i.e., with a thick mucilaginous sheath.

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

Pycnidia: Subglobular, unilocular. Conidia: Filiform or curved; microconidial, 13-20 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 + orange.

(report generated 04.Okt.2007)