Survive the competition for space.

Sunburst lichen (Xanthoria parietina) facing off against a Physcia lichen species. The striking colour difference is what immediately catches the eye, but there is another interesting observation to make about these two seemingly similar lichen species. Aside from the production of apothocia, the grey Physcia species is capable of another reproductive strategy, the production of soredia (not seen in photo). At soredia sites, the lichen will fragment into what looks like powder, tiny little pieces of the fungal partner wrapped around individual algae cells, to be dispersed by the wind and rain.

However, the yellow X. parietina lacks this additional reproductive strategy. Relying solely on sexual reproduction through the release of spores by their apothecia, the circular structures seen. To make up for decreased reproductive capacity it gains an edge with another characteristic. The orange coloured pigment parietin, which protects the growth of its algal partner by sheltering it from UV-B rays.

Two paths on the evolutionary tree, banking on different survival mechanisms, one on UV protection, and the other on more rapid dispersal and propagation.

Focus stack of 56 images.

Image size 3640 x 2600 pixels.

Actual size ~6mm wide x 4mm tall.