ITALIC 8.0

Acarospora mayrhoferi K.Knudsen & Kocourk.

Herzogia, 31: 511, 2018

Synonyms:

Distribution: N - TAA (Knudsen & Kocourková 2018, Knudsen & al. 2021), VA (Knudsen & Kocourková 2018).

Description: Thallus crustose, episubstratic, of scattered to contiguous, brown, epruinose, 0.5-1 mm wide, 0.35-0.55 mm thick, often black-edged areoles developing on the thalli of Dimelaena oreina. Cortex 25-40 μm thick, dark reddish brown in upper part, colourless in lower part; algal layer continuous under apothecia, uneven to even, intermixed with perpendicular hyphae, but not interrupted by distinct hyphal bundles; medulla thin, white. Apothecia lecanorine, immersed in the areoles, 1(-2) per areole, with a punctiform to slightly expanded, to 0.5 mm wide, dark brown, often rugulose, epruinose or lightly pruinose disc. Proper exciple narrow, c. 10 μm thick; epithecium reddish brown; hymenium colourless, 90-140 μm high, the hymenial gel euamyloid, IKI+ persistently dark blue; paraphyses c. 2 μm thick at mid-level, the apical cells up to 4 μm wide; hypothecium colourless. Asci 100-200-spored, clavate, the apical dome K/I-. Ascospores 1-celled, hyaline, broadly ellipsoid to globose 2-3 x 2 μm, or ellipsoid, 4-5 x c. 2 μm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: A recently-described species which grows parasitically on the thalli of Dimelaena oreina, hitherto known only from the Southern Alps (France, Italy).

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Subcontinental: restricted to areas with a dry-subcontinental climate (e.g. dry Alpine valleys, parts of Mediterranean Italy)

Paras Dimelaena oreina

Commonnes-rarity: (info)

Alpine belt: extremely rare

Subalpine belt: extremely 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

Index Fungorum GBIF

Kerry Knudsen - Source: Knudsen & Kocourková, Herzogia, 31,1, 2018

holotype. – A) Scattered areoles among the areoles of Dimelaena oreina. – B) Black-edged areoles, some bearing apothecia. – C) Detail of areoles with apothecia. Scale: 1 mm

Kerry Knudsen - Source: Knudsen & Kocourková, Herzogia, 31,1, 2018

(holotype: D; Kocourková 9007: E,F). – D) Vertical section of thallus showing continuous algal layer. – E) Young ascus with typical tholus and branched septate paraphyses. – F) Ascospores. – Scales: D,E = 20 μm; F = 10 μm.