Athallia holocarpa

Athallia holocarpa can be found almost everywhere — if you know where to look. This small crustose lichen thrives particularly well on nutrient-rich, acidic, hard surfaces such as brick, limestone, and concrete. It is also commonly found on the basalt of dykes. On trees, it favours hard patches of bark around areas where the bark has been damaged.

Lichens bear no resemblance whatsoever to mosses — the small green plants that grow in mats on rocks, soil, and trees. A lichen is actually a symbiotic partnership between an alga and a fungus: two entirely different organisms living together in perfect harmony.