Thermally induced chemical artifacts in lichens

Unsuspected thermal degradation of secondary products in lichens prior to chemical study, although probably uncommon, can lead to mistaken conclusions and taxonomic error. Thermally induced artifacts were found in the chemistries of Hypotrachyna partita from a site of volcanic activity in Costa Rica and in the type of H. prolongata from Haiti that had been dried for the herbarium with heat. In the Southern Appalachian Mountains normal material of H. prolongata has been considered a chemically different species. Thermal stability of secondary products may be an important factor in the chemical evolution of lichens inhabiting extreme environments.