SafePlants

Cracked Lichens: A Diverse Group of Organisms

Cracked lichens, often resembling cobblestone roads or cracked paint, represent a fascinating group of organisms with diverse appearances and ecological roles.

Considerations for Pets

• Some lichens grow on rocks, which can be rough or abrasive.

Considerations for Children

• Lichens often grow on rocks or tree bark, which could pose a slip hazard if climbed.

Scientific Names and Common Names

• Scientific Name: Acarospora (Genus)
• Common Names: Cracked Lichen, Cobblestone Lichen
• Examples of cracked lichen species include:
  • Acarospora hilaris
  • Acarospora schleicheri (Schleicher's Cracked Lichen)
  • Acarospora aeruginosa
  • Acarospora arenosa
  • Acarospora gallica (Gallic Cracked Lichen)
  • Acarospora impressula
  • Acarospora nodulosa (Nodule Cracked Lichen)
  • Acarospora badiofusca

Taxonomy and Nomenclature

• Kingdom: Fungi
• Phylum: Ascomycota
• Class: Lecanoromycetes
• Order: Agyriales
• Family: Acarosporaceae

Distribution and Habitat

• Cracked lichens can be found in various environments, including:
  • Desolate parts of the Rockies (for Narcotic lichen)
  • Rocky Mountains (for Schleicher's Cracked Lichen)
  • Planalto das Cezaredas, Portugal (for Acarospora nodulosa)
  • Sandstone cliffs

Morphological Characteristics and Growth Habits

• They often grow on rocks and can contribute to the breakdown of the rock surface over time.
• The lichen thallus (body) can be made up of separate lumps that eventually grow together, creating a continuous cracked surface.
• Some species exhibit a "cracked-areolate" thallus, where a continuous crust cracks during growth.
• Buellia subalbula is noted for its white, cracked thallus that appears slightly frosted.
• Some cracked lichens have a bright yellow areolate.

Interactions with Other Organisms

• Lichens can grow on trees and other plants.
• Lichens contribute to the weathering and breakdown of rocks.

Quirky Facts

• One type of cracked lichen, "Narcotic lichen", is described as rare and only grows in some desolate parts of the Rockies, with a humorous mention of a potential "sheep-based drug cartel."

Further Information

• plants.usda.gov
• HortHub.com
• Mushroom Observer (mushroomobserver.org)
• Catalogue of Life: 2012 Annual Checklist