Immersaria athroocarpa (Ach.) Rambold & Pietschm.

Data Set Maintenance: Data set standard item. Data set author(s): Hertel H. (C. Kainz, 03-06-03). Data set not revised.

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: species. Immersaria. Synonyms: Lecidea athroocarpa (Ach.) Ach., Lecidea fuscoatra var. athroocarpa, Porpidia athroocarpa (Ach.) Hertel & Rambold, Amygdalaria athroocarpa (Ach.) Clauz. & Roux, Porpidia afromontana Brusse; Lecideaceae Chevall. (1826) @EXCL@ Porpidiaceae Hertel & Hafellner (1984); Lecanorales.

Type Information: Basionym: Lichen athroocarpus Ach. ('L. athrocarpus'), Lich. Suec. Prodromus: 77 (1798).

Taxonomic Literature: Taxonomic notes: Thallus cortex 20-50 µm thick, upper cell layer brown to pale brown pigmented; hyphae c. 3-4.5 µm diam.; epinecral layer 35-95 µm thick;
Algal layer c. 65-120 µm thick; algal cells c. 9-11 µm, max. 13-15 µm diam.;
Medulla I+ violet; hyphae 3.5-7 µm thick;
Hypothallus black to grey, obvious between the areoles and at the thallus margin;
Asci c. 85-100 x 15-26 µm;
Pycnidia immersed, conidia cylindrical. Rambold G., Biblioth. Lichenol. 34: 1-346 (1989).

Biogeography: Continent: Africa, Australasia, Europe, and Northern America.

Ecology: Biotroph; lichenized; episubstratic; substrate non-calciferous.

Thallus: Areolate (primarily areolate); lobes more or less angular (with smooth surface, c. 0.5-0.7 mm, max. 0.8-1.2 mm diam.) at the front; separate thallus parts.1-.7 mm thick. Thallus Size and Differentiation: Large (up to 100 mm diam.). Upper Surface: Brown, plane (to concave).

Ascocarps: Forming independently from the host thallus or mycelium (dispersed to crowded), not emerging, 20-120 per cm², .6-(1.3) mm in diam.. Margin: Later excluded, indistinct (at first usually), 15-30 µm wide. Disk: Plane (to concave), black (to dark grey, matt), epruinose or pruinose. Exciple: Hyphae 3-4 µm wide; grey or dark brown (inner zone colourless to brownish). Epithecium: Apical cells brown (black- to green-). Hymenium: 85-125 µm high; white (I+ yellow to bluish, Iconc +/- orange-red). Subhymenium: 30-120 µm high; white (to brown). Hypothecium: Brown (dark to pale) or white (nearly).

Ascospores: Ellipsoid, 13-19.5-(23) µm long, (6)-7-9.5-(12) µm wide.

Conidia: 6-9-(12) µm long.

Secondary Metabolites: 2'-O-methylmicrophyllinic acid (three chemotypes observed), 2'-O-methylperlatolic acid, confluentic acid, or norstictic acid.

Spot Tests: Medulla: K –, C –, PD – ascocarp margin (in section): K –, C –.

(report generated 04.Okt.2007)