TAXONOMIC STUDIES IN FOLIICOLOUS SPECIES OF THE GENUS PORINA .1. THE PORINA-RUFULA AGGREGATE

An analysis of character variation in species of the Porina rufula agg regate, i.e. P. rufula (Kremp.) Vain., P. limbulata (Kremp.) Vain., P. rubentior (Stirt.) Mull. Arg., and P. pseudofulvella Serus., showed t hat the hitherto applied concepts of species delimitation - based on p erithecial size and colour - are not appropriate and should be replace d by a concept which primarily regards perithecial colour and shape as specific characters. Revision of type specimens proved the identity o f P. rufula and P. pseudofulvella, whereas P. limbulata sensu Santesso n had to be split into P. limbulata s. str. and P. leptospermoides Mul l. Arg. Evolutionary tendencies are seen in reduction of thallus morph ology and perithecial pigments as an adaptation to shady habitats, ind icating P. leptospermoides as a more primitive and P. rufula as a more advanced taxon. Judging from species distribution, the phylogenetic o rigin of the P. rufula aggregate might be in the Neotropics.