Stigmidium placynthii Cl. Roux & Nav. -Ros.

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 Data set author(s): Cáceres M. Data set not revised; not to be published after submission.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: Roux C. & Triebel D., Bull. Soc. Linn. Provence 45: 451-542 [515-517] (1994).

Biogeography: Mediterranean, montane and upper montane. Continent: Europe. Region(s): South-western Europe. Country or state(s): Spain (incl. Andorra & Monaco).

Ecology: Biotroph; lichenicolous, endosubstratic; growing on calciferous rock. Host or Phorophyte Taxonomy: Placynthium nigrum.

Thallus: Indistinct (vegetative hyphae hyaline).

Medulla: Iodine reaction in Lugol's solution negative.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Perithecioid, globose, forming inside the thallus or mycelium of the host, not emerging, abundant, 75-80 µm wide, with a black surface. Margin: Black, 6-10 µm wide. Exciple: Hyphae 1.5-3 µm wide, 3-9.5 µm long, brownish red. Periphyses: Present. Hymenium: Iodine reaction: Lugol’s negative, not hemiamyloid. Interascal Hyphae: Present, scarcely branched, not or scarcely anastomosed; cells 2.5-3 µm wide. Hypothecium: Brownish red.

Asci: Clavate or cylindrical (broadly subcylindrical), not stipitate or distinctly stipitate (shortly stipitate), 27-29 µm long, 9-11.5 µm wide; tholus not amyloid; ocular chamber present; dehiscence bitunicate; exoascus not amyloid, not hemiamyloid; ascoplasm not dextrinoid.

Ascospores: Not uniseriate, c. 8 per ascus, spores 8 per ascus, ellipsoid or oblong-obtuse, (7.5)-9.5-11.1-12-(13.5) µm long, 3-3.3-3.5-(4) µm wide, obtuse; septa present, transversally septate, 1-transversally septate; lumina of equal size or apically enlarged, constricted at the centre; wall thin, .5-1 µm wide, not constricted where the septum meets the spore wall, becoming pigmented, hyaline or pale brown (mature ascospores), in Lugol's Solution negative (internal perispore BCr-, then BCr+ dark blue), wall not ornamented, distinctly halonate, i.e., with a thick mucilaginous sheath.

Conidiomata: Absent resp. not observed.

(report generated 04.Okt.2007)