ITALIC 8.0

Psora mediterranea Evankow & Timdal

in Evankow & al., Mycol. Progr. 24, no. 26: 11, 2025.

Synonyms:

Distribution: S - Cal (Evankow & al. 2025).

Description: Thallus squamulose, the squamules up to 4 mm wide, rounded to elongate, scattered or contiguous to partly imbricate, weakly concave to weakly convex. Upper surface medium brown, dull or glossy, epruinose or partly pruinose, smooth or sparingly fissured, the margin white, straight or up-turned, entire or lobed; lower surface white to pale brown. Upper cortex up to 90-140 μm thick, of thick- to thin-walled hyphae with angular to round lumina, containing crystals of calcium oxalate; medulla white, with calcium oxalate crystals; lower cortex of mainly periclinally oriented hyphae,without crystals. Apothecia lecideine, up to 1.5 mm across, laminal or submarginal, medium brown to reddish brown, epruinose or yellow pruinose, with an initially flat, then convex disc and an initially evident, finally often excluded proper margin. Proper exciple poorly developed, of parallel hyphae; epithecium brownish, K+ red, N-; hymenium 50-70 μm high, colourless in lower half, brownish in upper part, amyloid; paraphyses simple or forked, hardly swollen at tips; hypothecium colourless or pale brown, with crystals of calcium oxalates. Asci 8-spored, elongate-clavate, with a thin, outer amyloid layer and a thickened tholus penetrated by a tube, the sides of which stain I/KI+ deep blue, without an ocular chamber, Porpidia-type. Ascospores 1-celled hyaline, ellipsoid, 10-14 x 5-7 μm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-; epithecium K+ red. Chemistry: thallus without lichen substances; apothecia with anthraquinones (mainly parietin).

Note: a recently-described, eu-Mediterranean to Mediterranean-montane species growing on limestone, both in fissures and directly on the compact stone surface, in sun-exposed to semi-shaded sites (see Evankow & al. 2025).

Growth form: Squamulose

Substrata: rocks, soil, terricolous mosses, and plant debris

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: absent

Oromediterranean belt: extremely rare

Montane belt: extremely rare

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: extremely rare

Humid mediterranean belt: extremely rare

Dry mediterranean belt: extremely rare

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: Evankow, A.M., Yin, A., Zulfiqar, R. et al. Psora mediterranea (Lecanorales, Psoraceae), a new lichen species from Europe, including a new concept for P. himalayana and a revised key to the European species. Mycol Progress 24, 26 (2025). https://doi.org/10.1007/s11557-025-02045-8 - CC BY 4.0

Greece
Holotype (Greece, O-L-22503, Photo: E. Timdal)