ITALIC 8.0

Rhizoplaca subdiscrepans (Nyl.) R. Sant.

The Lichens of Sweden and Norway: 278, 1984. Basionym: Squamaria chrysoleuca var. subdiscrepans Nyl. - Flora, 44: 718, 1861.

Synonyms: Lecanora subdiscrepans (Nyl.) Stizenb.; Sedelnikovaea subdiscrepans (Nyl.) S.Y. Kondr., L. Lőkös & Farkas; Squamaria chrysoleuca var. lecanorea Anzi?

Distribution: N - Lomb (Ravera & al. 2022b).

Description: Thallus crustose-placodioid to subsquamulose, loosely attached, pale yellowish green to whitish-green, rather glossy, of scattered to crowded, 0.3-1.3 mm wide, convex-bullate, sinuous and plicate areoles attached by a narrowed base, the marginal ones often slightly elongate. c. 1-2.5 mm long, 0.5-1.5 mm wide, discrete to slightly overlapping, convex, broadened and crenate-incised at tips, forming 1-5(-7) cm wide patches,. Upper cortex of strongly gelatinized hyphae, often heavily inspersed with brownish crystals soluble in K, the cell walls with isolichenan; medulla white, loose. Apothecia lecanorine, 0.7-2(-3) mm across, sessile and constricted at base, with a slightly concave to flat, pale pink to orange, pruinose disc, and a 0.1-0.2 mm wide, entire to flexuose, somewhat raised and slightly inflexed, usually persistent thalline margin. Proper exciple colourless, cupulate; epithecium orange-brown, covered with granules; hymenium colourless, 50-80 μm high, not inspersed with oil droplets; paraphyses simple to sparingly branched, the apical cells swollen, 3-5 µm wide. Asci 8-spored, clavate, the tholus with a strongly amyloid lateral part, a non-amyloid broadly diverging axial mass with a thick, non-amyloid cap above, and a weakly amyloid outer layer Lecanora-type. Ascospores 1-celled, hyaline, oblong, (8.5-)11-12(-13.5) x (3.5-)5-7 μm. Pycnidia black, immersed, with bluish-black ostioles. Conidia thread-like, (10-)15-25 µm long Photobiont chlorococcoid. Spot tests: cortex: K- or K+ yellow, C+ pale yellow, KC+ yellow, P-, UV-; medulla: K-, C-, KC-, P-, UV-. Chemistry: usnic and isousnic acid and variable amounts of either placodiolic or pseudoplacodiolic acid, plus an unidentified fatty acid and terpenoids.

Note: on the top of calciferous or basic siliceous boulders frequently visited by birds, with optimum above treeline. For further details see Szczepańska & al. (2020).

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: extremely 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

P.L. Nimis CC BY-SA 04

TSB 43979

Curtis Randall Björk – CC BY-SA 4.0

British Columbia, Clearwater Valley, Hemp Creek Canyonlands Date: 2011-06-01 On basalt boulder in open, dry forest

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (25985)
2001/12/01

Pier Luigi Nimis - CC BY-SA 4.0

TSB 43979