ITALIC 8.0

Rhizocarpon caeruleoalbum (Kremp.) Zahlbr.

Cat. Lich. Univ., 4: 331, 1927. Basionym: Rehmia caeruleoalba Kremp. - Denkschr. kgl. bayer. bot. Ges., 4, 2: 211, 1861.

Synonyms: Buellia coeruleoalba (Kremp.) Th. Fr.

Distribution: N - TAA (Nascimbene & al. 2022), Piem, VA (Piervittori & Isocrono 1999). C - Umb (Ravera & al. 2011).

Description: Thallus crustose, episubstratic, continuous to rimose-areolate, white to (bluish) grey-white, pruinose, forming patches to 5 cm in diam., rarely delimited by a black, but grey-pruinose prothallus. Areoles mainly angular, flat to slightly convex. Apothecia lecideine, black, 0.5-1.8 mm across, with a flat to weakly convex, epruinose or slightly pruinose disc, and a thick, persistent, usually pruinose proper margin. Proper exciple dark green-brown in outer part, pale brown to colourless within, containing K+ yellow crystals partly dissolving in K; epithecium olive-green, K+ intensifying green, with the same crystals as the exciple; hymenium colourless, 90-160 µm high; hypothecium dark brown, K-, without crystals. Asci 8-spored, clavate, fissitunicate, with a well-developed tholus, lacking an ocular chamber, Rhizocarpon-type. Ascospores 1-septate, hyaline or sometimes pale green when overmature, 13-20 x 5-10 µm, halonate. Photobiont chlorococcoid. Spot tests: medulla K+ yellow or rarely K+ yellow turning red, C-, KC-, P- or P+ orange. Chemistry: medulla with stictic acid, rarely with norstictic acid, or without lichen substances.

Note: on weakly calcareous or base-rich siliceous rocks, especially calcareous schists, with optimum above treeline.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: 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

Herbarium samples

Einar Timdal - Source: http://nhm2.uio.no/lav/web/index.html - CC BY-NC