SafePlants

Cracked Lichens (Acarospora spp.)

The term "cracked lichen" is a common name applied to various species within the genus Acarospora. These lichens are known for their distinctive appearance, resembling cracked cobblestone or old, cracked paint.

Considerations for Pets

• The text mentions lichens growing on rocks and other surfaces, and some species have a crusty or cracked texture. If pets ingest these lichens, consult a veterinarian, especially if unusual symptoms occur.

Considerations for Children

• Cracked lichens often grow on rocks and rough surfaces. Children should be supervised when exploring areas where these lichens are present to prevent falls or injuries.

Taxonomy and Nomenclature

• Genus: Acarospora
• Family: Acarosporaceae
• Common Names: Cobblestone lichens, Cracked lichens
• Examples of species mentioned include:
  • Acarospora hilaris
  • Acarospora aeruginosa
  • Acarospora albomarginata
  • Acarospora schleicheri (Schleicher's Cracked Lichen)
  • Acarospora nodulosa
  • Acarospora badiofusca
  • Acarospora socialis

Distribution and Habitat

• Cracked lichens often inhabit inhospitable regions.
• They can be found growing on rocks, including granite.
• Specific locations mentioned include:
  • Britain and Ireland
  • Idaho
  • Rocky Mountains
  • Planalto das Cezaredas, Portugal

Morphological Characteristics

• Cracked lichens have a thallus (body) that can appear cracked-areolate, meaning it is divided into small, distinct areas (areoles) separated by cracks.
• Initially, the thallus is made up of separate lumps that may grow together, forming a continuous, cracked surface.
• Some species, like one described as crustaceous, have angular, bright yellow areoles with small, darker apothecia (fruiting bodies) immersed within them.
• Buellia subalbula is mentioned to have a white cracked thallus.

Ecological Role

• Lichens, including cracked lichens, contribute to the weathering of rocks by slowly breaking them down.

Quirky Facts

• The text states that it can take decades for cracked lichens to grow over a single rock, highlighting their extremely slow growth rate.