Lichenized species of Omphalina (Tricholomataceae) in the Iberian Peninsula

A taxonomic revision of the lichenized species of the genus Omphalina in th e Iberian Peninsula is presented, based upon fungal and lichen herbarium ma terial, as well as on fresh collections. Relevant morphological and ecologi cal features are discussed and a diagnostic key is provided. Four lichenize d species, O. ericetorum, O. hudsoniana, O. meridionalis and O. velutina, a re recognized. A squamulose vegetative thallus (Coriscium-type) is present only in O. hudsoniana, while the other three species form a thallus of hyph al globules (Botrydina-type). Anatomical features of the vegetative thallus cannot be used to distinguish between these last three species. Whilst O. hudsoniana is known only from the montane belt of the Eurosiberian Region a nd O. meridionalis seems to be restricted to the Mediterranean Region, livi ng in more or less humid sites of the Supramediterranean belt, the other tw o species, O. ericetorum and O. velutina, are widespread. (C) 2001 The Brit ish Lichen Society.