Hypogymnia arcuata Tchaban. & McCune 2001
General description:
Lobe tips arcuate, curved upwards; lobes somewhat flattened; lower surface heavily perforate; similar to H. fragillima but lower surface less perforate and lobes shorter. Previously included under H. duplicata and H. enteromorpha f. inactiva. Closely related to H. fragillima, H. arcuata is separated from that species by the less frequently confluent holes in the lower surface, more broadly divergent branching, occasional fertility, and the usual presence of conphysodic acid by TLC. Formerly confused with the North American endemic H. duplicata, H. arcuata lacks the long, cascading lobes and physodalic and protocetraric acids of H. duplicata.