Four new and two resurrected species of Bacidina from Sweden, with notes and a preliminary key to the known Scandinavian species

Abstract

Four species of Bacidina (Ramalinaceae, Lecanorales, Ascomycota) are described as new to science from northern Europe (mainly Swedish material): Bacidina ferax S.Ekman, Bacidina lignicola S.Ekman, Bacidina maculans S.Ekman and Bacidina populnea S.Ekman. Another two species are resurrected from synonymy: Bacidina caerulea (Körb.) S.Ekman (based on Bacidia caerulea Körb.) and Bacidina circumpallens (Nyl.) S.Ekman (based on Lecidea circumpallens Nyl.). An additional four combinations are made: Bacidina friesiana (Hepp) S.Ekman (based on Biatora friesiana Hepp), Bacidina subfuscula (Nyl.) S.Ekman (based on Lecidea subfuscula Nyl.), Bacidina tarandina (Nyl.) S.Ekman (based on Lecidea tarandina Nyl.) and Bacidina tenella (Kullh.) S.Ekman (based on Bacidia tenella Kullh.). The morphology, distribution and nomenclature of all 28 species of Bacidina currently known from Scandinavia (Sweden, Norway, Denmark) are treated and an identification key is provided. In addition, Bacidina friesiana is discussed (for comparison with B. caerulea) even if it is not currently known from Scandinavia. Two of the treated species (B. epithallina ined., B. parasitica ined.) are parasites on cyanolichens but are not formally introduced here because of the scarcity of available material. Bilimbia arceutinoides Anzi is reduced to synonymy with Bilimbia sabuletorum (Schreb.) Arnold and Lecidea luteola var. chlorotica Ach. is reduced to synonymy with Bacidia rubella (Hoffm.) A.Massal. It is concluded that despite the present work, the diversity of the genus Bacidina remains insufficiently understood, at least in Scandinavia.