peltigera leucophlebia is a lichen with two different symbiontic algae: a green-algae and a cyanobacterium. The moisty lobes of the lichen are of a bright-greenish color (thats due to the green-algae) and show little black dots on their surface. These dots contain the cyanobacteria:
The following cross-section through a lobe gives us a closer look at the two photosymbionts:
The bright, green line consits of the green-algae. the protuberance below contains the dark-green symbiontic cyanobakteria. The white field above the green algae represents the fungus-mycelium.
