ITALIC 7.0

Rhizocarpon grande (Flörke ex Flot.) Arnold

Flora (Regensburg), 54: 149, 1871.. Basionym: Lecidea petraea f. grandis Flörke ex Flot. - Flora (Regensburg), 11, 2: 690, 1828.

Synonyms: Rhizocarpon endamyleum Th. Fr.

Distribution: N - TAA (Nascimbene & al. 2022).

Description: Thallus crustose, episubstratic, verrucose-areolate to bullate-verruculose, rather thick, grey-brown to pale grey, sometimes violet-tinged, rarely white-grey. Areoles up to 1.4(-2) mm wide, contiguous or more or less dispersed, constricted at base. Medulla white, faintly I+ blue. Apothecia lecideine, black, arising between the areoles, angular or rounded, up to 1.2(-1.5) mm across, with a flat to convex disc, and a thin, soon excluded proper margin. Proper exciple thin, K+ purple; epithecium reddish brown or black-brown, K+ purple; hymenium colourless to pale brown in upper part; paraphysoids coherent, capitate; hypothecium: brown, K-. Asci 8-spored, clavate, fissitunicate, with a well-developed tholus, lacking an ocular chamber, Rhizocarpon-type. Ascospores muriform, often aborted, dark brown, ellipsoid, 24-48 x 11-18 µm. Photobiont chlorococcoid. Spot tests: cortex K-, C+ pale pink; medulla K+ yellow or K-, C+ red, KC+ red, P+ orange, or P-. Chemistry: gyrophoric and barbatic acids, and variable amounts of stictic and norstictic acids.

Note: a silicicolous species resembling Rh. eupetraeum, but medulla with a different secondary chemistry, and ascospores larger; widespread in Europe, including the Alps, but the known distribution is lacunose, since the species was not always distinguished from Rh. eupetraeum. To be looked for further in the Italian Alps

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: very rare

Oromediterranean belt: absent

Montane belt: very rare

Submediterranean belt: extremely rare

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

Matthias Schultz - © - Nash et al. (2007) Lichen Flora of the Greater Sonoran Desert Region, Volume I