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), Piem.
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 underhanging 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:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

Botanische Staatssammlung München (M), M0084090 Holotype

Botanische Staatssammlung München (M), M0084090 – Source:

Botanische Staatssammlung München (M), M0084090 – Source:


Magnusson, AH (1952) Lichens from Torne Lappmark. Ark. Bot., ser. 2

Hertel, H (1977) Gesteinsbewohnende Arten der Sammelgattung Lecidea (Lichenes) aus Zentral-, Ost- und Sudasien. Khumbu Himal, Ergebnisse des Forschungsunternehmens Nepal Himalaya

Poelt, J/ Vezda, A (1981) Bestimmungsschlussel europaischer Flechten. Erganzungsheft II.