Symbiosis. We’re likin’ it

Leafy and flat lichen together

Leafy and flat lichen together

A feature of our landscape we tend to take for granted, yet is found everywhere (in the world), is lichen. Lichen is an organism resulting from a symbiotic (mutually beneficial) relationship between a fungus and either an algae or a particular bacteria. Like all good partnerships each contributes something to the union. The fungus part extracts minerals from the rocks or vegetation to which the lichen is attached, and it retains water. The algal part is photosynthetic and provides sugars by converting carbon dioxide from the atmosphere.


DSCN7654Simplistically, lichens can be grouped by their form. These include leafy (foliose), hair-like (filamentous), flat (crustose) and powdery (leprose). Just as other fungi are now starting to produce spore-bearing fruits (mushrooms) in the cooler weather, the fungi part of the lichen is doing the same. In the photos (right and below) a close look will reveal saucer-shaped bodies projecting from the lichen body. The inner surface of these saucers is lined with spore-bearing cells. When the spores are ripe they are ejected from the saucer and combine with an algal partner to form another lichen.

DSCN7801Like most things, when you are aware of them you find them all over the place. So when you are outdoors next, check out the lichen. They truly are everywhere.