SUMMARYSuccessful resyntheses were achieved between a mycobiont ofCladonia cristatellaand 13 isolates ofTrebouxiaphycobionts. The same mycobiont did not establish symbiotic associations with 10 isolates ofPseudotrebouxiaphycobionts or with the free-living algaPleurastrum terrestre.The mycobiontLecanora chrysoleucaformed soredia with five isolates ofPseudotrebouxiaand with one isolate ofTrebouxia.The synthesized squamules were identical in morphology to the natural squamules ofC. cristatella—they produced mature pycnidia and short podetia with immature apothecia. Concentric bodies were seen in the hyphae ofC. cristatellasynthesized with the phycobionts ofCladonia boryiandLecidea tumida.