SafePlants

Cracked Lichen: An Overview

The term "cracked lichen" refers to various lichen species, often appearing like a cobblestone road or cracked paint on rocks and other surfaces. They belong to the genus Acarospora and the family Acarosporaceae.

Considerations for Pets

• Some sources mention lichens growing on rocks, which could pose a minor ingestion hazard for pets if they lick or chew on them.

Considerations for Children

• The cracked surface of some lichens might be tempting for children to pick at, potentially leading to ingestion of small pieces.

Taxonomy and Nomenclature

• Genus: Acarospora
• Family: Acarosporaceae
• Common Names: Cobblestone lichen, cracked lichen
• Examples of Species:
  • Acarospora aeruginosa Hasse - cracked lichen
  • Acarospora albomarginata (Herre) Salisb. - cracked lichen
  • Acarospora schleicheri - Schleicher's Cracked Lichen
  • Acarospora nodulosa - Nodule Cracked Lichen
  • Acarospora socialis - Cracked Lichen
  • Acarospora badiofusca - Cracked lichen

Distribution and Habitat

• Cracked lichens can be found in various locations. One source mentions Schleicher's Cracked Lichen in the Rocky Mountains.
• Narcotic lichen, possibly a type of cracked lichen, is rare and grows in desolate parts of the Rockies.

Morphological Characteristics

• Cracked lichens often have a "cracked-areolate" thallus, where a continuous crust cracks during growth.
• The thallus may initially consist of separate lumps that grow together to form a continuous, cracked surface.
• Some species, like Buellia subalbula, have a white, cracked thallus that appears frosted.
• Cracked lichens can grow on various surfaces including rocks, bark and soil.

Ecological Role

• Lichens, including cracked lichens, contribute to the slow breakdown of rocks.

Quirky Facts

• One source lightheartedly alludes to the possibility of a "sheep-based drug cartel" in relation to a rare "narcotic lichen" found in the Rockies, though this should be taken with a grain of salt!