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Physconia perisidiosa  (Erich.) Moberg

Synonyms:

Family: PHYSCIACEAE

Habitat: Ubiquitous

Description

    Thallus foliose, rosette-shaped, 2-5 cm diam., loosely appressed to the substratum, composed of lobes, intricate, radiating, short, 1-1.5 mm wide, pruinose towards margins, brown-greenish, pale brownish, pale greyish, occasionally tinged purple mainly towards the center, covered with dull white labriform soralia, mostly marginal, and with a few isidia, lower surface center dark brown, much paler towards the margins, margin devoid of cortex, brown rhizines, bottle-brush-shaped. Apothecia very rare, thalline exciple with sorediate lobules. Ascospores brown, thick walls, 1-septate, 26-35 x 16-21 µm. Chemical spot test negative, notably white medulla is  K-.  Rare species growing on nutrient-rich substrata on mossy trunks of ornmental trees aligned along roads or in parks sometimes on rocks and walls. See  Physconia enteroxantha of which the yellow medulla is K+ yellow. See also Physconia grisea which has simple rhizines and Physconia detersa montane and boreal species with only marginal soralia and longer radiant lobes.







Physconia perisidiosa Montmedy 1
Jacques HAINE



Physconia perisidiosa Drôme provençale 1
Jacques HAINE



Physconia perisidiosa Ardèche 1
Jacques HAINE



Physconia perisidiosa Ardèche 2
Jacques HAINE



Physconia perisidiosa en mèlange avec Physconia distorta var. subvenusta Ardèche 3
Jacques HAINE



Physconia perisidiosa Ardèche 4
Jacques HAINE



Physconia perisidiosa Coupe du thalle Ardèche 5
Jacques HAINE



Physconia perisidiosa Rhizine Ardèche 6
Jacques HAINE



Physconia perisidiosa Drôme provençale 2
Jacques HAINE



Physconia perisidiosa Drôme provençale 3
Jacques HAINE



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