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Physcia adscendens H. Olivier

Synonyms:

Family: PHYSCIACEAE

Habitat: Ubiquitous

Description

    Thallus foliose, loosely appressed to the substratum, to 5 cm across (when confluent with other colonies), lobes 0.5-1 mm wide, apices up-turned, bent and swollen, hood or helmet-shaped, containing pale yellow to cream soredia; lobe margins bearing long marginal cilia (0.5-2 mm) with dark tips, upper surface whitish, pale grey when dry, grey-greenish when moist, without pruine, dotted with numerous whitish pseudocyphella, lower surface whitish with rhizines, tips blackish. Seldom fertile and with rare apothecia, 1-2 mm diam., shortly stalked, disc brownish to blackish, pruinose, exciple thick. Ascospores brownish, 1-septate, 16-23 x 7-10 µm. Pycnidia sometimes abundant and visible as black dots. Cortex K+ yellow; medulla: K-. Not especially maritime, common on tree barks, even within cities, equally abundant on nutrient-rich rocks and sometimes on cement. See Physcia tenella, very similar and sometimes difficult to distinguish, but the latter has not hood-shaped lobe tips and its soredia are labriform (this species is considered by some authors as identical and intermediate specimen between the two species may be found as well as chimeras). See also Physcia leptalea which is not sorediate. The morphs of Physcia adscendens H. Olivier  presented here are those growing on tree barks. Those described under the name of Physcia adscendens f.  correspond to morphs growing on rocks, notably near the seashore.*







Physcia adscendens sur écorce Le Faou
Bernard BOUFFINIER



Physcia adscendens sur écorce Telgruc
Bernard BOUFFINIER



Physcia adscendens sur écorce Le Guilvinec 1
Bernard BOUFFINIER



Physcia adscendens Le Fret
Michel DAVID



Physcia adscendens sur écorce Le Fret 2
Bernard BOUFFINIER



Physcia adscendens et Physcia leptalea sur écorce Le Guilvinec 2
Bernard BOUFFINIER



Physcia adscendens Fertile sur écorce Le Guilvinec 3
Bernard BOUFFINIER



Physcia adscendens sur écorce Lannion 1
Bernard BOUFFINIER



Physcia adscendens sur écorce Lannion 2
Bernard BOUFFINIER



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