Natural History Photographs


Some fungi are associated with two symbionts, a green alga and a cyanobacterium. The morphology of the lichen depends very much on the symbiont, which can be seen especially well in Sticta canariensis. The fungus may live together with either the green alga or the cyanobacterium - the result being a completely different morphology. Sometimes you may find composite thalli, in which the green algal morph thallus develops from the cyanobacterial thallus.
Sticta canariensis
Synonyms:Sticta dufourii


green algal photomorph


cyanobacterial photomorph


composite thalli


In contrast to Sticta canariensis, the species shown here below are true tripartite symbioses. In these lichens, the cyanobacterial photobiont is located in structures that clearly stand out from the remaining thallus; such structures are called cephalodia.
Amygdalaria spec.

In the right-most photo, the cephalodia are highlighted.
Nephroma arcticum
English:Arctic kidney-lichen
Peltigera aphthosa
Nederlands:Grasgroen leermos
Deutsch:Warzige Apfelflechte
Placopsis gelida
Nederlands:Grote zeepkorst
English:Flesh-coloured alpine lichen
Deutsch:Braunes Bullenauge