Cetraria muricata (Ach.) Eckfeldt

    Thallus fruticose, forming dense shrubs, cushion-like, 1-4 cm high, composed of markedly divided branches, section irregular, slightly flattened (not terete nor canaliculate), surface glossy or varnished-like, branch endings  characterized by branching into several points or spinules, some branches covered with stiff cilia or minute spinules, apices blackish, pseudocyphellae flat, rounded, scarce, absent from surface depressions, overall colour brown-greenish when moist, brown-reddish to brown-chocolate when dry. Apoothecia very scarce, disc brown-red, exciple ciliate. Photobiont: chlorococcoid. Chemical spot tests negative. Scarce in our prospection area, on ground in highly exposed Erica heathlands near the seashore. Not to be confused with Cetraria islandica and Cetraria ericetorum of which branches are flattened and canaliculate. N.B. Very close to Cetraria aculeata, devoid of spinules and stiff cilia, up to be considered by some authors as simple ecoforms and with all intermediate specimen between the two forms. Cetraria muricata grows in much more exposed environments and simply might be a fom of  Cetraria aculeata  subjected to harsh conditions. Additional investigations are required in order to clarify this issue.