Roccella fuciformis forma
Thallus erect and tufted, branches often not tight, markedly branched toward apices, attached by a single holdfast, more or less flattened towards the base, soralia marginal, pustulose, whitish, overall colour pale grey-brownish tinged with purple or violet, medulla white including including sections close to holdfast. Very seldom fertile, apothecia flat, disc black. Cortex: C+ red, faint red orange, labile. Rare, on cliffs exposed to S-W together with Roccella fuciformis s.l. that differs by its C reaction: pink on soredia and C- on cortex. Grows also together with Roccella phycopsis. N.B. This taxon seems to operate the transition between Roccella maderensis and Roccella allorgei growing in the Macaronesian islands, with partial common chemical reactions (except K+ yellow). Additional research would required to clarify its status.
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.