Stigmidium mitchellii Cl. Roux & Bricaud

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 Data set author(s): Cáceres M. Data set not revised; not to be published after submission.

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: species. Stigmidium. Genus incertae sedis: Stigmidium; of unknown placement (incertae sedis).

Taxonomic Literature: Taxonomic notes: Roux C. & Triebel D., Bull. Soc. Linn. Provence 45: 451-542 [496-498] (1994).

Biogeography: Northern hemispheric, colline. Continent: Europe. Region(s): Northern Europe. Country or state(s): United Kingdom (Ireland).

Ecology: Biotroph; lichenicolous, endosubstratic. Host or Phorophyte Taxonomy: Pannaria conoplea.

Thallus: Indistinct. Upper Surface: Brown (vegetative hyphae pale brown).

Medulla: Iodine reaction in Lugol's solution positive (hyphae strongly BCr+ blue violet intense).

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Perithecioid, globose or subglobose, forming inside the thallus or mycelium of the host, not emerging, becoming adnate, moderately abundant, 50-60 µm wide, 55-65 µm high, with a black surface. Margin: Black, 4-10 µm wide. Exciple: Paraplectenchymatous; hyphae 1-3 µm wide, 3-11 µm long, brownish red. Periphyses: Present. Interascal Hyphae: Present, scarcely branched, not or scarcely anastomosed; cells 2-3 µm wide. Hypothecium: Pale brownish red.

Asci: Clavate, not stipitate, 28-35 µm long, 10-14 µm wide; ocular chamber present; dehiscence bitunicate; ascoplasm dextrinoid (endoascus BCr+ violet).

Ascospores: Not uniseriate, c. 8 per ascus, spores 8 per ascus, ellipsoid, (10.5)-12-12.8-14-(14.5) µm long, 3-3.6-4-(5) µm wide, obtuse; septa present, transversally septate, 1-transversally septate; lumina more or less of equal size; wall thin, laterally constricted where the septum meets the spore wall, remaining hyaline, hyaline, in Lugol's Solution positive (epispore BCr+ pale violet and perispore BCr+ intense blue), wall not ornamented.

Conidiomata: Present.

Conidia: Cylindrical; 2.5-3 µm long, .5-1 µm wide.

(report generated 04.Okt.2007)