Two new Micarea species ( Pilocarpaceae ) from Western Europe

[摘要] Two new Micarea species, M. minuta and M. pseudotsugae, are described from the Netherlands based on morphological, chemical and molecular data. Micarea minuta belongs to the M. denigrata group and can be distinguished from other similar species of this group by its small apothecia, Sedifolia-grey pigment in the epihymenium, mostly 1-septate and small ascospores, 40–80 μm wide mesopycnidia, and the lack of secondary lichen metabolites detectable by thin-layer chromatography. Micarea pseudotsugae is a member of the M. prasina group and is characterized by an areolate, granular to subsquamulose thallus, the presence of methoxymicareic acid, the lack of Sedifolia-grey pigment, the presence of crystals (visible in polarized light) in the apothecia only, and one type of conidia (mesoconidia). The phylogenetic position of the newly described species was studied based on mtSSU rDNA marker analysis; M. minuta was found to be closely related to M. denigrata, M. nitschkeana and M. subnigrata, while M. pseudotsugae was found to be closely related to M. byssacea and M. laeta. Notes on secondary chemistry, ecology, distribution and phylogeny are given.

[关键词] Ascomycota;corticolous species;Lecanorales;lichens;molecular phylogenetics;secondary chemistry;taxonomy