Parmotrema mordenii (Hale) Hale, 1974
Parmotrema mordenii is recognizable by the adnate thallus, eciliate lobes, presence of soralia and medulla with atranorin (K+ yellow, P+ slowly weak yellow). In P. praesorediosum the soralia are usually crescent-shaped and atranorin is lacking in the medulla. Although Sipman (2005) also treat these two species as distinct, Krog & Swinscow (1981) putted P. mordenii as synonym of P. praesorediosum.
In the protologue of P. mordenii, Hale (1971) stated that the soralia could occasionally form coralloid subfatiscent structures. We found in the specimen collected some pustular, capitate soralia that remember this description, however, more material is necessary to prove if this is also a good feature to take this species apart from P. praesorediosum.
[Spielmann & Marcelli 2009].