ITALIC 8.0

Rufoplaca tristiuscula (H. Magn.) Arup, Søchting & Frödén

Nord. J. Bot., 31: 74, 2013. Basionym: Caloplaca tristiuscula H. Magn. - Bot. Not.: 50, 1944.

Synonyms:

Distribution: N - TAA (B 60 0195727).

Description: Thallus crustose, episubstratic, rather thick, dark grey to blackish grey, rimose-areolate to verruculose, forming large patches. Cortex paraplectenchymatous; medulla poorly evident. Apothecia zeorine, sessile, round to angular by mutual compression, 0.5-1.2 mm across, with an initially concave, then flat, orange to dark orange disc, a persistent, smooth, thin, distinctly paler proper margin, and a dark grey, finally often excluded thalline margin. Thalline exciple with abundant algae; proper exciple prosoplectenchymatous, with anthraquinone crystals; epithecium inspersed with orange-yellow crystals of anthraquinones reacting K+ red; hymenium colourless; paraphyses simple to sparingly branched in upper part, the apical cells up to 5 μm wide; hypothecium colourless. Asci 8-spored, clavate, functionally unitunicate, apically thickened with a broad internal beak, the inner part of apex and external cap I+ blue, Teloschistes-type. Ascospores 2-celled, polarilocular, narrowly ellipsoid, 10-16 x 4.5-7 μm, the equatorial thickening (“septum”) 2.5-4 μm. Photobiont chlorococcoid. Spot tests: thallus K- or K+ weakly violet in section, C- or C+ violet, KC-, P-; disc of apothecia K+ red. Chemistry: thallus with the Sedifolia-grey pigment; disc of apothecia with unchlorinated anthraquinones.

Note: a poorly known species described from Sweden, growing on base-rich siliceous rocks in subalpine-alpine areas, also reported from the Austrian Alps; the Italian sample, identified by J. Poelt, was collected by Buschardt in Val Venosta at c. 500 m.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Poorly known taxon in need of further study

Commonnes-rarity: (info)

Alpine belt: very rare

Subalpine belt: very rare

Oromediterranean belt: absent

Montane belt: absent

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

Jan Vondrak - Source: https://botanika.prf.jcu.cz/lichenology/index.php?pg=8&cat=32&idx=913 Germany Hessen Hohe Rhön Wirth897

Jan Vondrak - Source: https://botanika.prf.jcu.cz/lichenology/index.php?pg=8&cat=32&idx=913

Germany Hessen Hohe Rhön Wirth897