ITALIC 8.0

Rhizocarpon geographicum subsp. frigidum (Räsänen) Hertel

in Hertel & Ullrich, Mitt. bot. Staatss. München, 12: 483, 1976. Basionym: Rhizocarpon frigidum Räsänen - Ann. Bot. Soc. Zool.-Bot. Fenn. Vanamo, 19: 9, 1944.

Synonyms: Rhizocarpon tinei subsp. frigidum (Räsänen) Runemark

Distribution: N - TAA, Lomb, VA (Piervittori & Isocrono 1999).

Description: Thallus crustose, bright yellow-green, areolate, forming patches 1-5 cm in diam., delimited by a black prothallus which is often visible also as a hypothallus between areoles. Areoles angular, 0.3-1 mm wide, dispersed or contiguous, flat to slightly convex, smooth, epruinose, usually glossy. Cortex 30-60 µm thick, without distinct structure; medulla white, I+ blue. Apothecia frequent and numerous, lecideine, arising between the areoles, angular, 0.3-0.9 mm across, 0.2-0.6 µm thick, with a black, flat, epruinose disc, and a thin, usually persistent proper margin. Proper exciple pale brown to brownish red; epithecium reddish brown to reddish violet, K+ distinctly red; hymenium 110-160 µm thick, colourless to greenish, K/I+blue; paraphysoids strongly conglutinate, richly branched and anastomosing, clavate; hypothecium dark brown, K-. Asci 8-spored, clavate, fissitunicate, with a well-developed tholus, lacking an ocular chamber, Rhizocarpon-type. Ascospores muriform, with a few septa, soon becoming dark green to brown, ellipsoid, 20-32 x 10-14 µm, halonate. Photobiont chlorococcoid. Spot tests: medulla K-, C-, KC-, P+ yellow. Chemistry: cortex with rhizocarpic acid; medulla with psoromic acid; epithecium with gyrophoric acid.

Note: an arctic-alpine lichen found on steeply inclined to rqain-sheltered surfaces of siliceous rock above treeline; restricted to the Alps, where it can reach the nival belt.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: rather rare

Subalpine belt: rare

Oromediterranean belt: absent

Montane belt: absent

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

Index Fungorum GBIF

P.L. Nimis CC BY-SA 4.0

TSB 26194

Pier Luigi Nimis; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (26194)