ITALIC 8.0

Verrucaria mediterranea Thüs & Nascimbene

in Nascimbene & al., J. Fungi, 9, 380: 18, 2023

Synonyms:

Distribution: C - Sar (Thüs & Nascimbene 2023).

Description: Thallus crustose, episubstratic, pale brown to pale grey, c. 0.15 mm thick, rimose to areolate, the areoles c. 0.3 mm wide, not gelatinous when wet. Pseudocortex with a brownish pigment; medulla at least in some spots with a black basal layer, otherwise hardly distinguishable. Perithecia black, ⅔ to fully immersed in the thallus, with a distinct involucrellum reaching down to the basis of the perithecium, attached to exciple but thickened at base, forming a conical structure; exciple dark brown throughout; hamathecium of up to 50 μm long and 1.5-1.8 μm thick periphyses, interascal filaments absent. 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, c. 64 × 19 μm. Ascospores 1-celled, hyaline, narrowly ellipsoid, 15-21 x 6-8.4 μm, 1.9-3.3 times as long as wide. Photobiont chlorococcoid, the cells mostly globose and 8-10 μm across, but some interspersed cells elongate and up to 20 x 10 μm. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: a recently-described species growing on siliceous rocks in the splash zone of Mediterranean streams, hitherto known only from Sardinia.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Periodically submerged (e.g. in creeks)

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: absent

Oromediterranean belt: absent

Montane belt: very rare

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: very rare

Humid mediterranean belt: very 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

Source: Nascimbene & al. 2023

Italy, Sardinia
Holotype of Verrucaria mediterranea sp. nov., SMNS-STU-F-0001654 (STU). (A) Outer morphology. (B) Section of a perithecium with ascospores, and surrounding thallus. Scale bars in (A) = 1 mm, in (B) = 100 µm.