Acta Soc. Fauna Flora fenn. 49(no. 2): 265 (1921).

Basionym: Lichen membranaceus Dicks., Fasc. pl. crypt. brit. (London) 2: 21 (1790).

Chemistry: Thallus c-, K- to + yellow, PD+ reddish-orange. A sample of 38 specimens studied by TLC shows that the species comprises a simple chemotype containing both pannaric acid (present in all specimens) and roccellic acid (present in all specimens), with atranorin (present in 19 specimens) frequently present, and zeorin (present in three specimens) infrequently present, as accessories (Laundon 1989: 9). Roccellic acid (Huneck & Yoshimura 1996: 154).

Note: Pannaric acid, C16H12O7, was described from Leproloma membranaceum by Hesse (1903: 57) ... Pannaric acid is unusual amongst lichen compounds in being apparently water-soluble ... (Laundon 1989: 9).