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Diploschistes caesioplumbeus (Nyl.) Vain.

Synonyms:

Diploschistes actinostomus var. caesioplumbeus (Nyl) J. Steiner



Family: GRAPHIDACEAE

Habitat: Xeric supralittoral  zone

Description

     Thallus crustose, rather thick and with an aspect similar to Aspicilia, more or less smooth and shiny, areolate, cracked, with a conspicuous characteristic colour: lead-grey to blue-grey, edged by a dark-grey or pale grey prothallus. Apothecia 0.1-0.2 mm diam., immersed in areoles, resembling to perithecia (or like a wheel with tire), sometimes several per areole, leaving a small opening depressed, with marginal excipular hairs visible as a ciliate fringe or radiating ribs. Ascospores broadly ellipsoid, dark brown, muriform, 30-45 x 11-24 µm. Photobiont : Trebouxia. K-, C+ red, KC+ red, Pd-. On siliceous rocks near the sea shores in the well-lit supralittoral zone, this species is a parasite of other crustose lichens that are gradually replaced. Ascii (2)-4-8-spored (depending on aborted spores during further development), apex beak-shaped, 80-120 x 30-40 µm according to our measures. Ascospores broadly ellipsoid, colourless at first (sometimes I+ purple in lugol), then brown, muriform, 5-9 transversal septa and 2-4 longitudinal, 30-45 x 11-24 µm according to literature, 27-45 x 20-25 (30) according to our measures. Photobiont: Trebouxia. K+/- yellow, C+ red, KC+ red-orange, Pd-. Parasite of other crustose lichens during its early stages of its development, extending to the whole host thalli on siliceous rocks in the foreshore well-lit supralittoral zone. According to our observations, the most frequently parasited  species is Tephromela atra and  Lecanora gangaleoides (see the pictures of Diploschistes caesioplumbeus forme parasite de Tephtomela atra et de Lecanora gangaleoides). It is often competing with Lecanora sulphurea that, when young, is itself sometimes a parasite of Tephromela atra, but it seems that in the course of this competition, Diploschistes caesioplumbeus may become itself a prey of Lecanora sulphurea (see Lecanora sulphurea vs Diploschistes caesioplumbeus). N.B. This taxon was sometimes named  Diploschistes actinostomus that in fact is a paler taxon, greyish but not grey-blue, with smaller ascospores: 20-40 x 10-15 µm (but the distribution curves of ascospores sizes of these 2 taxa overlap!), not especially coastal (but not rare in this habitat) and not parasite at first. All the intermediate forms between these two taxa exist.







Diploschistes caesioplumbeus Habitat Kerascoet 2
Bernard BOUFFINIER



Diploschistes caesioplumbeus Pointe d'Armorique 3
Alain GERAULT



Diploschistes caesioplumbeus Pointe de Kerdra
Bernard BOUFFINIER



Diploschistes caesioplumbeus Pointe d'Armorique 2
Alain GERAULT



Diploschistes caesioplumbeus Kerascoet
Bernard BOUFFINIER



Diploschistes caesioplumbeus Pointe de Pen-Hir 1
Bernard BOUFFINIER



Diploschistes caesioplumbeus Port Merrien
Bernard BOUFFINIER



Diploschistes caesioplumbeus Kerloc'h
Michel DAVID



Diploschistes caesioplumbeus Pointe d'Armorique 1
Bernard BOUFFINIER



Diploschistes caesioplumbeus Beg ar Minéou 4
Joël QUERELLOU



Diploschistes caesioplumbeus Beg ar Minéou 3
Joël QUERELLOU



Diploschistes caesioplumbeus Beg ar Minéou 2
Joël QUERELLOU



Diploschistes caesioplumbeus Beg ar Minéou 1
Joël QUERELLOU



Diploschistes caesioplumbeus Crozon 2
Jacques HAINE



Diploschistes caesioplumbeus Habitat sur muret de pierres en bordure de mer. Iles de Glénan 1
Alain GERAULT



Diploschistes caesioplumbeus RĂ©action au C Crozon 4
Jacques HAINE



Diploschistes caesioplumbeus RĂ©action au K Crozon 5
Jacques HAINE



Diploschistes caesioplumbeus RĂ©action au KC Crozon 6
Jacques HAINE



Diploschistes caesioplumbeus Coupe apothécie Eau Crozon 7
Jacques HAINE



Diploschistes caesioplumbeus Asque eau Crozon 8
Jacques HAINE



Diploschistes caesioplumbeus Asques eau Crozon 9
Jacques HAINE



Diploschistes caesioplumbeus Asque Bleu Coton 10
Jacques HAINE



Diploschistes caesioplumbeus Spores Lugol 11
Jacques HAINE



Diploschistes caesioplumbeus Spores Eau Crozon 12
Jacques HAINE



Diploschistes caesioplumbeus Habitat sur muret de pierres en bordure de mer. Iles de Glénan 2
Alain GERAULT



Diploschistes caesioplumbeus Iles de Glénan 3
Alain GERAULT



Diploschistes caesioplumbeus Iles de Glénan 4
Alain GERAULT



Diploschistes caesioplumbeus Iles de Glénan 5
Alain GERAULT



Diploschistes caesioplumbeus Cap de la Chèvre 1
Bernard BOUFFINIER



Diploschistes caesioplumbeus Cap de la Chèvre 2
Bernard BOUFFINIER



Diploschistes caesioplumbeus Cap de la Chèvre 3
Bernard BOUFFINIER



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