Sphaerellothecium araneosum (Rehm ex Arnold) Zopf

Data Set Maintenance: Data set compiled. Data set author(s): Cáceres M. (03-05-20). Data set not revised; not to be published after submission.

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: species. Sphaerellothecium. Dacampiaceae Körb. (1855); Dothideales.

Taxonomic Literature: Roux C. & Triebel D., Bull. Soc. Linn. Provence 45: 451-542 [519] (1994).

Biogeography: Northern hemispheric, submontane, montane, subalpine, and alpine. Continent: Europe, Northern America, and Southern America. Region(s): Northern Europe, Middle Europe, and Southern South America (dry and subtropical). Country or state(s): Norway, Sweden, Austria, and Switzerland (incl. Liechtenstein); Greenland; Southern Chile (Chile).

Ecology: Biotroph; lichenicolous; endosubstratic or episubstratic (vegetative hyphae forming a reticulum on the thallus of the host); growing on inorganic soil, bark, or calciferous rock. Host or Phorophyte Taxonomy: Ochrolechia upsaliensis; Pertusaria sp.; Varicellaria rhodocarpa.

Lichen Photobionts: Primary photobiont absent.

Thallus: Indistinct (vegetative hyphae brown, torulose).

Medulla: Iodine reaction in Lugol's solution positive (vegetative hyphae BCr+ dark blue).

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Perithecioid, globose or subglobose, forming inside the thallus or mycelium of the host, within the ascocarp margin of the host or within the ascocarp disks of the host, not emerging, becoming adnate, moderately abundant (gregarious), 40-100 µm wide, with a black surface. Wall: Not carbonized. Margin: Black, 7-17-(20) µm wide; external filaments absent. Disk: Smooth. Exciple: Paraplectenchymatous; hyphae 1-6 µm wide, 3.5-11 µm long; not carbonized; dark brown. Periphyses: Present (very distinct, 7-13 x 1.5-3.5 µm). Hymenium: Iodine reaction: Lugol’s negative, not hemiamyloid. Interascal Hyphae: Present, scarcely branched, not or scarcely anastomosed; cells 1.5-3 µm wide. Hypothecium: Dark brown.

Asci: Globose (exceptionally subglobose), clavate, or broadly cylindrical, distinctly stipitate (shortly stipitate), 34-45 µm long, 14-16 µm wide; tholus not amyloid; ocular chamber present; indistinct; dehiscence bitunicate (fissitunicate); exoascus not amyloid, not hemiamyloid.

Ascospores: Not uniseriate, c. 8 per ascus, spores 8 per ascus, ellipsoid, oblong-obtuse, or sub clavate, (12.5)-13.5-15.1-17-(22) µm long, (3.5)-5-5.9-7-(7.5) µm wide, obtuse; septa present; transversally septate, 1-(3)-transversally septate; lumina of equal size or apically enlarged, constricted at the centre; wall thin, not constricted where the septum meets the spore wall or laterally constricted where the septum meets the spore wall, becoming pigmented, middle brown or hyaline, not ornamented or ornamented (interne perispore becoming brownish and distinctly granulose), distinctly halonate, i.e., with a thick mucilaginous sheath.

Conidiomata: Present.

Conidia: 2.5-3.5 µm long, 1-1.5 µm wide.

Secondary Metabolites: Not detected.

(report generated 04.Okt.2007)