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Caloplaca ceracea J. R. Laudon

Synonyms:

Caloplaca caesiorufa auct. brit.



Family: TELOSCHISTACEAE

Habitat: Xeric supralittoral  zone

Description

   Thallus crustose, areolate, surface roughened, widespreading, pale to dark grey, grey-greenish when moist, to 5 cm diam., prothallus inconspicuous or absent. Apothecia numerous, usually crowded, to 1 mm diam., rounded to flexuose; proper margin thick, swollen, matt, persistent for a long while and looking like small caruncles when old, paler than disc, yellow-orange to yellowish; disc flat or very slightly convex matt brown-orange, olive brown, bright brown when dry, and greenish to olive-green when moist, contrasting with exciple. This green colour is due to algae, forming a dense continuous green layer of closely packed cells running beneath a colourless hypothecium (visible in sections) and is characteristic of this species. Ascospores polarilocular, ellipsoid, septum 3-5 µm wide, about 1/3 of the length of the ascospore, 13-15 x 8 µm according to literature, 14-17 x 6-8 µm, septum de 5-7 µm wide according to our measures. Photobiont : trebouxioid. Thallus K-, apothecia K+ purple. Common, on slightly acid siliceous nutrient-rich rocks, in sheltered and little lit habitats from the xeric-supralittoral zone  to the terrestrial-halophilic zone subjected to spray. Frequently confused with species belonging to the Caloplaca crenularia cluster that can extend to marine environments but distinct by its apothecia, bright brown-rusty slightly convex with a concolourous exciple, disappearing later and by the lack of greenish colour on the whole surface of apothecia (but many intermediate specimen exist, difficult to determine). Confused synonymy with closely related species, notably Caloplaca subpallida. Caloplaca ceracea is a highly variable species, strictly dependent on its habitat, and althought several taxa may be described under the name of Caloplaca ceracea, we suggest here to restrict its use to a well characterized taxon of the xeric supralittoral zone. N.B. A different taxon, growing on slightly acid or calcareous rocks, or on mortar of old walls, in little-lit areas near the foreshore may be found: Caloplaca ceracea forma. Its thallus is thicker, green-yellow and apothecia more brown-orange tinged olivaceous with bright yellow exciple.

 

 







Caloplaca ceracea Sainte Anne la Palud 2
Bernard BOUFFINIER



Caloplaca ceracea Le Passage
Alain GERAULT



Caloplaca ceracea Sainte Anne la Palue 1
Alain GERAULT



Caloplaca ceracea Le Fret 2
Bernard BOUFFINIER



Caloplaca ceracea Le Fret 1
Bernard BOUFFINIER



Caloplaca ceracea Sainte Anne la Palud 3
Bernard BOUFFINIER



Caloplaca ceracea Sainte Anne la Palud 4
Bernard BOUFFINIER



Caloplaca ceracea Pointe de Dinan 1
Bernard BOUFFINIER



Caloplaca ceracea Pointe de Dinan 2
Bernard BOUFFINIER



Caloplaca ceracea Landévennec 1
Jacques HAINE



Caloplaca ceracea Coupe apothécie Landévennec 2
Jacques HAINE



Caloplaca ceracea Asque, paraphyses, photobionte Landévennec 3
Jacques HAINE



Caloplaca ceracea Spores eau Landévennec 4
Jacques HAINE



Caloplaca ceracea Arzon
Michel DAVID



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