ITALIC 8.0

Arthonia subvarians Nyl.

Flora, 51: 345, 1868

Synonyms: Arthonia galactinaria Leight.

Distribution: N - TAA (Brackel 2015, 2016, Hafellner & Grube 2023). C - Tosc (Brackel 2015, 2016), Abr (Brackel 2015, 2016, Gheza & al. 2021). S - Pugl (Brackel 2015, 2016), Si (Brackel 2008c, 2016).

Description: Thallus inapparent, not lichenized, forming discoloured patches on the apothecia of Polyozosia-species. Apothecia arthonioid, black, epruinose, convex and cushion-like, irregularly rounded, 0.1-0.2 mm across. Proper exciple very poorly developed; epithecium brown, K-, I+ rust-red, K/I+ blue; hymenium colourless, I+ red, K/I+ blue; paraphysoids branched and anastomosing, the apical cells swollen; hypothecium colourless. Asci (4-)8-spored, broadly clavate, semi-fissitunicate, with a large apical dome and a distinct ocular chamber, Arthonia-type. Ascospores 1-septate, with a cell wider and longer than the other, not or only slightly constricted at septum, at first hyaline but soon turning pale brown, soleiform, 9-13 x 4-5 μm, smooth-walled. Photobiont absent. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: this lichenicolous fungus is widespread and quite common in Europe and is also known from Asia, North America, northern Africa, and New Zealand. It seems to be restricted to Polyozosia-species, especially P. dispersa s.lat., whereas the very similar Arthonia lecanorina grows on Lecanora albella. Collections of Arthonia clemens (which is restricted to Rhizoplaca) on epilithic lecanoroid lichens were reported from several localities in Italy; they may belong to A. subvarians or to A. apotheciorum, which grows on Polyozosia albescens. The epithet subvarians has been often used for a species which is lichenicolous on species of the Lecanora polytropa complex, but according to Hafellner & Grube (2023) it is the correct name for A. galactinaria.

Growth form: Lichenicolous fungus

Substrata: rocks

Reproductive strategy: mainly sexual

paras Polyozosia spp.

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: absent

Oromediterranean belt: absent

Montane belt: rare

Submediterranean belt: rare

Padanian area: absent

Humid submediterranean belt: rare

Humid mediterranean belt: rare

Dry mediterranean belt: rare

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; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (35696)
2003/01/21
in the apothecia of the host, Lecanora flotowiana

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_A/Textes_A3/Arthonia_galactinaria.htm

France, Chalet de Laval, Névache, 2024 m - Hautes-Alpes
4/6/2017

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_A/Textes_A3/Arthonia_galactinaria.htm

France, Chalet de Laval, Névache, 2024 m - Hautes-Alpes
4/6/2017

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_A/Textes_A3/Arthonia_galactinaria.htm

France, Chalet de Laval, Névache, 2024 m - Hautes-Alpes
4/6/2017

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_A/Textes_A3/Arthonia_galactinaria.htm

France, Chalet de Laval, Névache, 2024 m - Hautes-Alpes
4/6/2017

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_A/Textes_A3/Arthonia_galactinaria.htm

France, Chalet de Laval, Névache, 2024 m - Hautes-Alpes
4/6/2017