Crustose lichens

Mostly crustose lichens overlaying moist rocks

Various lichens, particularly the crustose group, thriving on a farmer's field-clearing cache of rocks located in the shade of a woodland edge.

Crustose Lichens:
Colorful Showmanship

By William T. Hathaway

As the name implies, crustose lichens tend to form a crust or outer covering on the surface layer of soils, rocks and wood. On many farms an older pile of rocks, gathered to clear fields, will host a lichen species, especially if the rock pile is in partial shade. Most rock piles may seem commonplace. However, a closer look often reveals intricate lichenose patterns, tinged with delicately pale colors.

Lichens may be defined as any of various small plants composed of a particular fungus and a particular alga growing in an intimate symbiotic association. This coming together forms a dual plant, interfacing with its chosen surface. With the coming of rain and moist conditions, crustose lichens may transform from a crusty dullness to a patch of colorful showmanship.

Also see this illustration in larger format.


Notes: