Roccella phycopsis DC forma
This form (under investigation) is an intermediate between Roccella phycopsis (owing to its yellow holdfast) and Roccella tinctoria (due to its bright C+ carmine). Shrubby, forming dense tufts, more or less rounded, 3-5 cm diam., branches markedly ramified with secondary digitate branches. Overall colour pale, ochre with lilac tinge or dull light green-blue. On vertical walls or under the overhangs of siliceous rocks little exposed to the sun in Brittany islands.
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.