Lecidella asema (Nyl.) Knoph & Hertel

Data Set Maintenance: Data set compiled and standard item. Data set author(s): Kainz C. (01-06-10). Data set reviewer(s): Knoph J.-G. (03-10-22); revised; to be published after submission.

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: species. Lecidella. Synonyms: Lecidella subincongrua (Nyl.) Hertel & Leuckert; Lecidea distrata
Arnold; Lecidea distratula Zahlbr.; Lecidella elaeochromoides (Nyl.)
Knoph & Hertel; Lecidea parasema (Ach.) Ach. var. elaeochromoides
Nyl.; Lecidea subincongrua Nyl. var. elaeochromoides Poelt; Lecidea
catalinaria Stiz.; Lecanoraceae Körb. (1855).

Type Information: Basionym: Lecidea asema Nyl. 1872. Flora 55: 356.

Taxonomic Literature: Knoph J.-G. 1990. Untersuchungen an gesteinsbewohnenden
xanthonhaltigen Sippen der Flechtengattung Lecidella (Lecanoraceae,
Lecanorales) unter besonderer Berücksichtigung von
außereuropäischen Proben exclusive Amerika. Bibl.
Lichenologica 36: 1-183 [66-71; 103-107 sub L. elaeochromoides].
Leuckert, C., Knoph, J.-G. & Hertel, H. (1992): Chemotaxonomische Studien in der Gattung Lecidella (Lecanorales, Lecanoraceae) II. Europäische Arten der Lecidella asema-Gruppe. - Herzogia 9: 1-17 [3-6; 7-9 sub L. elaeochromoides].
Knoph, J.-G. & Leuckert, C. (1994): Chemotaxonomic studies in the saxicolous species of the lichen genus Lecidella (Lecanoraceae, Lecanorales) in America. - Nova Hedwigia 59: 455-508 [466-469; 480-484 sub. L. elaeochromoides].

Biogeography: Continent: Africa (Teneriffa, North Africa), Asia-Temperate, Europe, and Northern America.

Ecology: Biotroph; lichenized; terricolous, lignicolous, or corticolous; substrate non-calciferous.

Thallus: Crustose, strongly rimose or areolate (primarily areolate); separate thallus parts thin or thick ((> 1.8 mm)). Thallus Outline: Soon disappearing. Upper Surface: Black (older herbarium specimens), white, pale grey (older herbarium specimens), or lemon (citrine), matt or glossy (shiny), smooth (to isidia-like dissolved, very variable); sorediate.

Medulla: Iodine reaction in Lugol's solution negative.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Soon sessile, strongly constricted at the base, .5-1.5 mm in diam.. Margin: Lecideine/biatorine, persistent, distinct or indistinct (0.05-0.1 mm). Disk: Plane or weakly convex, black or hyaline brown (when damaged), epruinose. Exciple: Carbonized; white (sometimes) or dark green (pale to rarely strongly). Parathecium (proper excipulum): Pale brown, inspersed with crystals (often). Amphithecium (thalline excipulum): Present. Epithecium: Apical cells slightly swollen, dark green, turquoise (olivaceous, rarely), or olive. Hymenium: 55-90 µm high; white. Hypothecium: Pale brown or pale brownish red.

Ascospores: c. 8 per ascus, ellipsoid, 9-16 µm long, 5.5-8 µm wide; septa absent; wall thick (not halonate), distinctly differentiated into primary and secondary wall (not halonate), not ornamented (not halonate).

Pycnidia: Globular. Conidiophores: Vobis-type III. Conidia: Filiform or strongly curved; 20-30 µm long.

Secondary Metabolites: 2,4-dichloronorlichexanthone, 2,5-dichloronorlichexanthone, 2,7-dichloro-6-O-methylnorlichexanthone, 2,7-dichloronorlichexanthone, 3-O-methylasemone (= 4,5,7-trichloro-3-O-methylnorlichexanthone), 3-O-methylthiophanic acid (= 2,4,5,7-Tetrachloro-3-O-methylnorlichexanthone), 4,5-dichloro-3-O-methylnorlichexanthone, 4,5-dichloro-6-O-methylnorlichexanthone, 4,5-dichloronorlichexanthone, arthothelin (2,4,5-trichloronorlichexanthone), asemone (= 4,5,7-trichloronorlichexanthone), atranorin, chloroatranorin (in traces), isoarthothelin (= 2,5,7-trichloronorlichexanthone), thiophanic acid (= 2,4,5,7-tetrachloronorlichexanthone), or thuringione (= 2,4,5-trichloro-3-O-methylnorlichexanthone), of the following substance class(es): xanthones.

Spot Tests: Upper surface: K – (negative) or + deep yellow (rarely), C + orange, PD – or + yellow (rarely).

(report generated 04.Okt.2007)