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Opegrapha niveoatra (Borrer) J. R. Laundon

Synonyms:

Family: ROCCELLACEAE

Habitat: Ubiquitous

Description

    Thallus crustose, very thin, superficial, sometimes inconspicuous, more or less smooth, sometimes cracked, whitish, greyish, brown-greyish, brown-olivaceous. Apothecia lirelliform, small, 0.5-1 x 0.1-0.2 mm, little prominent, 0.05-0.1 mm height, simple, straight or curved, seldom forked, disc slit-shaped, opening gradually with maturation, rough, blackish. Ascus 80-90 x 12-15 µm according to our measurement. Ascospores quite elongated, acicular, 4-7-septate, 20-30 x 2,5-4 µm, and 25-30 x 3-4,5 µm, according to literature and our measurement respectively. Pycnidia always present, numerous, blackish, producing short and curved conidia (N.B. There are specimens with only pycnidii but linked to fertile specimens by intermediary ones). Chemical spot tests negative. Inconspicuous species, on alkaline or neutral bark of deciduous trees. See Opegrapha vulgata of which the apothecia are larger and the conidia larger, straight or sickle-shaped.*







Opegrapha niveoatra Crozon 2
Bernard BOUFFINIER



Opegrapha niveoatra Crozon 1
Bernard BOUFFINIER



Opegrapha niveoatra sur Tilia Belgique Couvin 1
Jacques HAINE



Opegrapha niveoatra coupe lirelle Eau Belgique Couvin 2
Jacques HAINE



Opegrapha niveoatra Aspect général Bleu Coton Belgique Couvin 53
Jacques HAINE



Opegrapha niveoatra Asques et paraphyses Bleu Coton Belgique Couvin 54
Jacques HAINE



Opegrapha niveoatra Asques Eau Belgique Couvin 55
Jacques HAINE



Opegrapha niveoatra Asques Lugol Belgique Couvin 56
Jacques HAINE



Opegrapha niveoatra Conidies Lugol Belgique Couvin 57
Jacques HAINE



Opegrapha niveoatra Spores Lugol Belgique Couvin S8
Jacques HAINE



Opegrapha niveoatra Crozon 3
Bernard BOUFFINIER



Opegrapha niveoatra Crozon 4
Bernard BOUFFINIER



Opegrapha niveoatra forme avec uniquement des pycnides Crozon 5
Bernard BOUFFINIER



Opegrapha niveoatra forme avec uniquement des pycnides Crozon 6
Bernard BOUFFINIER



Opegrapha niveoatra forme avec uniquement des pycnides Crozon 7
Bernard BOUFFINIER



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