Published online by Cambridge University Press: 19 July 2007
Argüello et al. (2007) found that Parmelina quercina, as circumscribed by Hale (1976), comprised four phylogenetic species which could also be distinguished by morphological features and also had different distributions: P. carporrhizans (usually rhizinate apothecia, and distinct effigurate maculae; oceanic Europe and Macaronesia), P. coleae (usually rhizinate apothecia, narrow ascospores, and fenestrate maculae; North America), P. elixia (non-rhizinate apothecia, larger ascospores, smaller conidia, and not or faintly maculate; Australia), and P. quercina (apothecia rhizinate or not, and less distinct more rounded maculae; continental Europe).