Seven Graphis species are reported as new to Europe from the Serra de Sintra and the Planalto das Cezaredas, two regions of Portugal where graphidoid Graphidaceae are abundant and diverse. The following species were identified: Graphis cincta, G. crebra, G. handelii, G. leptospora, G. lineola, G. plumierae, and G. verminosa. Many of these share two characters: a densely inspersed hymenium and the presence of norstictic acid in the thallus. A key to the Graphis species known from Europe is provided. The possible reasons for the high, previously unknown, diversity of graphidoid Graphidaceae in this region are discussed. Global warming might be a contributory factor.