Roccella phycopsis forme corticole.

    This form differs from the type by its habitat: bark on tree trunks, usually near chapels where walls are covered with numerous colonies of Roccella phycopsis wall form. Thallus erect, in small rounded tufts, 1.5-3 cm high, located at trunk mid-height, composed of tightened branches, more or less distorted, some forked, apices sections flattened or ovoid, soralia numerous, laminal or marginal, lenticular or farinose, white, overall colour pale grey-greenish tinged with blue. Holdfast medulla yellowish. Rare and always sterile. Observed only on Fagus of parish enclosures of chapels near the seashore.

Tehler A., Dahlkild A., Eldenäs P. & Feige G.B. 2004. The phylogeny and taxonomy of Macaronesian, European and Mediterranean Roccella (Roccellacea, Arthoniales). Acta Univ. Ups. Symb. Bot. Ups. 34:1, 405-428.