ITALIC 8.0

Verrucaria euganea Trevis.

Spighe e Paglie: 19, 1853.

Synonyms: Verrucaria crozalsii B. de Lesd.; Verrucaria obductilis var. reticulata B. de Lesd.; Verrucaria transiliens auct. non (Arnold) Lettau; Verrucaria weddellii auct. non Trevis.

Distribution: N - Ven (Breuss 2008b, Breuss & Berger 2010), TAA (Nascimbene 2005), Piem, Emil (Nimis & al. 1996, Fariselli & al. 2020), Lig. C - Marc (Nimis & Tretiach 1999), Umb (Genovesi & al. 2002, Ravera & al. 2006). S - Pugl (Nimis & Tretiach 1999), Bas (Nimis & Tretiach 1999).

Description: Thallus crustose, episubstratic, 0.15-0.3 mm thick, rimose-areolate, pale to medium brown, with an olive-green hue when wet, forming several cm wide patches, the areoles 0.3-0.9 mm wide, uneven, rounded or angular, with wavy margins. Cortex 8-25 μm thick; algal layer 80-130 μm thick; medulla white to patchily brownish, often containing rock particles. Perithecia black, sparse, c. 10-15/cm², hemispherically projecting from the areoles, the flanks covered by a thin thalline layer, the apical part naked, 0.3-0.5 mm across. Involucrellum reaching down at least halfway (often to base-level), forming an arch above the exciple, well-separated by an undifferentiated tissue, c. 50-80 μm thick, sometimes slightly thinner at the base; exciple globose, (0.35-)0.5-0.7 mm across, the wall 35-45 μm thick, brown to blackish brown; hamathecium of branched and anastomosing, 70-100 μm long periphysoids, interascal filaments absent; hymenial gel hemiamyloid, I+ red (I+ blue at very low concentrations of I), K/I+ blue. Asci 8-spored, clavate, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of an endotunica to form a delicate rostrum, Verrucaria-type. Ascospores 1-celled, hyaline, ellipsoid, 27-35 x 14-17 μm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: an early coloniser of walls (mortar, brick, cement, limestone) in urban settlements; related to V. macrostoma, but differing in several important morphological characters (see Breuss 2008b, Breuss & Berger 2010). This species was almost always confused with V. transiliens (see e.g. Roux & coll. 2025); I have placed here all records by Italian authors of V. transiliens, except those by Sbarbaro, whose material was probably identified by Servít.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

In underhangs rarely wetted by rain

Pioneer species

Poorly known taxon in need of further study

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: absent

Oromediterranean belt: absent

Montane belt: very rare

Submediterranean belt: rare

Padanian area: extremely rare

Humid submediterranean belt: rare

Humid mediterranean belt: rare

Dry mediterranean belt: absent

pH of the substrata:

1

2

3

4

5

(info)

Solar irradiation:

1

2

3

4

5

(info)

Aridity:

1

2

3

4

5

(info)

Eutrophication:

1

2

3

4

5

(info)

Poleotolerance:

0

1

2

3

(info)

Altitudinal distribution:

1

2

3

4

5

6

(info)

Predictive model

INDEX FUNGORUM GBIF DOLICHENS

S. Poumarat - Source: http://mycologie.catalogne.free.fr/lichens.htm

Source: M. Servit, Sbornik Narodniho musea v Praze. V. B. (1949) No. 9. Tab. I. – Public Domain

Source: Breuss O. 2008b. Bemerkungen zu einiger Arten der Flechtengattung Verrucaria. Sauteria, 15: 121-138. Author: Othmar Breuss