DEVELOPMENT OF THE THALLI OF EREMASTRELLA -CRYSTALLIFERA AND THEIR TAXONOMIC SIGNIFICANCE (PSORACEAE, ASCOMYCOTINA)

The development of the ''crystal-like'' thalli of Eremastrella crystal lifera is examined by means of light and scanning electron microscopy. At the first stage of development only few rims are visible on the up per surface of the thallus and the algal layer is continuous. During t he development, the photobiont is concentrated in groups, and therefor e the algal layer becomes discontinuous. The cortex splits reticulatel y and belongs in old thalli to the ''Kegelrindentyp'' after Poelt. You ng thalli are morphologically and anatomically not distinguishable fro m Psora-thalli. Therefore it is proposed to reduce the generic name Er emastrella to synonymy with Psora. The new name Psora almborniana is i ntroduced for Eremastrella montana Brusse.