ITALIC 8.0

Thelidium acrotellum Arnold

Flora, 49: 532, 1866.

Synonyms:

Distribution: N - TAA (Dalla Torre & Sarnthein 1902, Nascimbene & al. 2022).

Description: Thallus crustose, thinly episubstratic, continuous and film-like, brownish grey, greenish when wet. Perithecia black, 0.1-0.15 mm across, partially immersed in the rock, the emergent part hemispherical, often somewhat flattened at apex, sometimes partly covered by a thin thalline layer. Involucrellum limited to the apical third of the perithecium, adpressed to exciple; exciple colourless to very pale brown; hamathecium of periphyses and periphysoids, interascal filaments absent; hymenial gel I+ red (I+ blue at very low concentrations of I), K/I + blue. Asci (6-)8-spored, ellipsoid to clavate, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of a delicate rostrum. Ascospores 1-septate, hyaline, ellipsoid, often pointed at both ends, 15-21 x 6-8 μm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: on more or less calciferous rocks in upland areas: according to Breuss (2004) the species is not easy to distinguish from T. minutulum, but has a colourless excipulum and a thin involucrellum.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Pioneer species

Commonnes-rarity: (info)

Alpine belt: extremely rare

Subalpine belt: very 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

Source: Zschacke, H. (1934) Epigloeaceae, Verrucariaceae und Dermatocarpaceae. In: Dr. L. Rabenhorst‘s Kryptogamen-Flora, Band 9, Abt. 1, Teil 1. Akademische Verlagsgesellschaft, Leipzig, 695 pp. - Public Domain