Melanolecia transitoria (Arnold) Hertel

in Poelt & Vezda, Bibl. Lichenol., 16: 365, 1981. Basionym: Lecidea transitoria Arnold - Flora, 53: 123, 1870.
Synonyms: Lecidea henricii Zahlbr.; Lecidea subcoerulescens Arnold; Tremolecia transitoria (Arnold) Hertel
Distribution: N - Ven (Hertel & Schuhwerk 2010), TAA (Hertel & Schuhwerk 2010, Nascimbene & al. 2022), Piem, VA (TO 2250).
Description: Thallus crustose, fully endosubstratic, poorly evident, often pale blue-green. Apothecia immersed in pits of the rock, 0.2-0.7(-1) mm across, glossy black, epruinose, with a flat to weakly convex disc and a thin but evident, more or less persistent proper margin. Proper exciple thick, carbonized, black throughout; epithecium blue-green, grey-green or green-brown, c. 15 μm high; hymenium colourless to pale green or pale brown, 40-70 μm high; paraphyses coherent, richly anastomosing, 1.7-2 µm thick at mid-level, the apical cell up to 3.5 µm wide; hypothecium brown-black, slightly paler than exciple, K+ red-brown. Asci 8-spored, narrowly clavate, thick-walled, with a K/I+ pale blue tholus and a strongly amyloid, thin apical cushion, surrounded by a I+ blue outer layer, Lecidea-type. Ascospores 1-celled, hyaline, ellipsoid, 8-12.5(-14) x 4-7.5 μm, halonate at least when young. Pycnidia black, globose, immersed. Conidia bacilliform, 3.5-8 µm long. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: thallus without lichen substances.
Note: a circumpolar, arctic-alpine lichen found on inclined to rain-sheltered surfaces of calcareous rocks above treeline; probably restricted to the Alps, where it reaches the nival belt.
Growth form: Crustose endolithic
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: very rare
Subalpine belt: absent
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:

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Solar irradiation:

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Aridity:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model
Herbarium samples

Botanische Staatssammlung München (M), M0084090 https://plants.jstor.org/stable/10.5555/al.ap.specimen.m0084090 Holotype


Botanische Staatssammlung München (M), M0084090 – Source: https://plants.jstor.org/stable/10.5555/al.ap.specimen.m0084090
Holotype


Botanische Staatssammlung München (M), M0084090 – Source: https://plants.jstor.org/stable/10.5555/al.ap.specimen.m0084090
Holotype