DEVELOPMENT, REGENERATION, AND PARASITIC INTERACTIONS BETWEEN THE LICHENS FULGENSIA-BRACTEATA AND TONINIA-CAERULEONIGRICANS

A possible source of Trebouxia algae for lichens are the thalli of lic hens that are attacked by another mycobiont that captures the algae fo r its own symbiotic use. Such a process is described for Fulgensia bra cteata living in parasitic association with Toninia caeruleonigricans. The development of the thalli of Toninia and the parasitic attack of Fulgensia are analysed in detail. The infection of Toninia is achieved by ascospores and can be demonstrated by the presence of secondary li chen substances typical for Fulgensia, which occur in infected thalli of Toninia. Fulgensia also overgrows other lichens, but these thalli a re not invaded. The special abilities of Toninia and various methods f or distribution and regeneration compensate for the parasitism and the association remains stable. The ecology of the small developmental st ages of Toninia and Fulgensia shows important differences.