ITALIC 8.0

Verrucaria nigrofusca Servít

Acta Mus. Nat. Pragae, 5, B, 9, Bot. 3: 38, 1949.

Synonyms: Lithoicea nigrescens var. umbrina A. Massal.; Verrucaria nigroumbrina Servít

Distribution: N - Ven, Lig.

Description: Thallus crustose, episubstratic, dull brown, continuous to rimose-areolate, 0.2-0.3 mm thick, sometimes delimited by a thin black prothallus, the areoles angular to irregular, flat, smooth, 0.2-0.5 mm wide (the fertile ones up to 0.8 mm wide), often subdivided into smaller units. Cortex poorly developed, brown in uppermost part; medulla white or patchily brown (especially around perithecia), sometimes pale brown in lowermost part, but without a black basal layer. Perithecia black, 1 per areole, almost fully immersed or hemispherically projecting, without a thalline covering. Involucrellum adpressed to exciple, extending to base-level, up to 80-100 µm thick at base; exciple subglobose to broadly pyriform, 0.2-0.3 mm across, the wall colourless to dark brown, 15-20 µm thick; hamathecium of 25-35 µm long, thin, mostly simple periphyses and 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, 17-24 x 8-12 µm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: a very poorly known species, described from the Czech Republic and also reported from France (Maritime Alps), on both calcareous and basic siliceous rocks. According to Breuss (2016) it differs from V. fuscoatroides in the smaller perithecia and spores.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Poorly known taxon in need of further study

Commonnes-rarity: (info)

Alpine belt: very rare

Subalpine belt: very rare

Oromediterranean belt: absent

Montane belt: extremely rare

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: absent

Humid mediterranean belt: absent

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

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