STATUS OF THE LICHEN GENUS PORPIDIA IN EASTERN FENNOSCANDIA

Developing species concepts for Porpidia are tested in Finland and adj acent Russia, an area where the genus has been collected abundantly bu t has not been revised recently. Fifteen entities are included and nam ed at the species level. Four are excluded or expected. A key is provi ded for included and expected taxa, and the status of each as a specie s is discussed. The original publications of names, basionyms, and sel ected synonyms are cited. The following are new to Europe: P. lowiana Gowan, P. thomsonii Gowan, and an unnamed sorediate counterpart to P. macrocarpa (DC.) Hertel & Knoph. The following are new to Finland: P. contraponenda (Arnold) Knoph & Hertel, P. grisea Gowan, P. musiva (Koe rber) Hertel & Knoph, P. speirea (Ach.) Krempelh., P. superha (Koerber ) Hertel & Knoph, and specimens that may belong to P. soredizodes (Lam y ex Nyl.) Laundon. Several basionyms and synonyms are typified, conce ntrating on taxa described by W. Nylander and E.A. Vainio from the stu dy area. Porpidia pseudomelinodes Schwab is transferred to Hymenelia a s H. ochrolemma (Vainio) Gowan & Ahti, comb. nov. An earlier lectotypi fication of Lecidea flavocoerulescens Hornem. is rejected and a new on e proposed, in an attempt to stabilize the use of the name, as follows : Porpidia flavocoerulescens refers to a nonsorediate species. Porpidi a melinodes (Koerber) Gowan & Ahti, comb. nov. refers to a sorediate s pecies.