ITALIC 8.0

Rhizocarpon geographicum subsp. prospectans (Räsänen) D. Hawksw. & Sowter

Trans. Leicester Lit. Phil. Soc., 63: 58, 1969. Basionym: Rhizocarpon prospectans Räsänen - Ann. Bot. Soc. Zool.-Bot. Fenn. Vanamo, 19: 8, 1944.

Synonyms: Rhizocarpon tinei subsp. prospectans (Räsänen) Runemark

Distribution: N - Lomb.

Description: Thallus crustose, bright yellow-green, 0.2-0.4 mm thick, areolate, forming patches to 10 cm diam., delimited by a black prothallus. Areoles more or less angular, irregularly subdivided by cracks, 0.4-3 mm wide, contiguous, flat, smooth, epruinose. Cortex without distinct structure, with abundant small crystals not soluble in K; medulla white, I+ blue. Apothecia frequent, lecideine, arising between the areoles and often surrounded by collar-like areoles, rounded, 0.4-1.5 mm across, with a black, weakly concave to weakly convex, epruinose disc, and a very thin, often indistinct, black proper margin. Proper exciple pale brown to brownish red; epithecium brown, K-; hymenium 110-160 µm thick, colourless to greenish, K/I+blue, K+ greenish; paraphysoids strongly conglutinated, richly branched and anastomosing, sometimes slightly capitate; hypothecium dark brown, K-. Asci 8-spored, clavate, fissitunicate, with a well-developed tholus, lacking an ocular chamber, Rhizocarpon-type. Ascospores muriform, with 6-13 cells visible in optical view, soon becoming dark green to brown, ellipsoid, 22-32 x 10-14 µm, halonate. Photobiont chlorococcoid. Spot tests: medulla K-, C-, KC- , P-. Chemistry: rhizocarpic acid.

Note: on exposed surfaces of base-rich siliceous rocks. A western lichen in Europe, which needs further study.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)

Poorly known taxon in need of further study

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: extremely rare

Oromediterranean belt: absent

Montane belt: very 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

P.L. Nimis CC BY-SA 4.0

TSB 1063

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

Herbarium: TSB (1063)