Français English

Arthonia spadicea  Leighton

Synonyms:

Family: ARTHONIACEAE

Habitat: Ubiquitous

Description

     Thallus crustose, very thin, more or less immersed, usually not well delimited, pale grey, pale grey-green, almost transparent and leaving bark colour visible below. Apothecia  more or less round-shaped, 1-1,5 mm in diam., flat to slightly convex, red-brown, chocolate,  to brown-black, often slightly glossy, resembling spots of tar. Ascospores ovoid or slipper-shaped, 1-septate, colourless, 7-11 x 3-4 µm. Pycnidia frequent, 0.1mm diam., brown. Photobiont : Trentepohlia. Chemical spot tests negative except apothecia and pycnidia slightly K+ purple (weak reaction). Uncommon, on very shaded bark of trunks (usually at or near base) of basic barked, deciduous trees of moist woodlands. Cf. Arthonia vinosa with thallus orange spotted, apothecia more convex and orange and smaller ascospores; and  Arthonia didyma with much smaller apothecia.*







Arthonia spadicea Ardennes 1
Jacques HAINE



Arthonia spadicea Ardennes 2
Jacques HAINE



Arthonia spadicea Ardennes 3
Jacques HAINE



Arthonia spadicea Asque
Jacques HAINE



Arthonia spadicea Spore
Jacques HAINE



Arthonia spadicea Trégarvan 1
Bernard BOUFFINIER



Arthonia spadicea Trégarvan 2
Bernard BOUFFINIER



Arthonia spadicea ForĂȘt du Cranou 2
Bernard BOUFFINIER



Arthonia spadicea ForĂȘt du Cranou 1
Bernard BOUFFINIER



Arthonia spadicea ForĂȘt du Cranou 3
Bernard BOUFFINIER



Arthonia spadicea ForĂȘt du Cranou 4
Bernard BOUFFINIER



Return
Content : Alain Gérault - Website development : Sylvain Ard - Hosting : Online.net