Roccella phycopsis forme des murs.
This form differs by its habitat, usually old walls of chapels exposed to the North or East near the seashore. Thallus erect, in small tufts 1-3 cm high, branches with terete section during early development, more or less flattened at the end, branched towards apices. Overall colour dull earth-grey. This form, apparently sterile, is often parasited, and subjected to various interactions with numerous crustose lichens in the same environments.
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.