SafePlants

Cracked Lichen: A Study in Resilience

Cracked lichens, often resembling a cobblestone road or cracked paint, are a fascinating group of organisms known for their extreme rarity and slow growth. They thrive in some of the most inhospitable regions.

Considerations for Children

• The text mentions lichens associated with cracked or fragile skin, although this is in reference to a medical condition and not the lichen itself.
• Some images show cracked lichens on rocks that could be sharp.

Scientific Classification and Nomenclature

• The text mentions the genus Acarospora, with several species referred to as "cracked lichen."
• Family: Acarosporaceae
• Genus: Acarospora
• Symbol: ACARO2

Common Names

• Cracked Lichen
• Cobblestone Lichen

Distribution and Habitat

• Cracked lichens grow in very inhospitable regions.
• Specific locations mentioned include Idaho and Planalto das Cezaredas, Portugal.
• They are found on various substrates, including granite and sandstone cliffs.

Morphological Characteristics

• They may look like a cobblestone road or cracked up old paint.
• They often exhibit a 'cracked-areolate' thallus, where a continuous crust cracks during growth.
• The lichen thallus is initially made up of separate lumps that grow together to produce a continuous cracked surface.
• Some species, like Buellia subalbula, have a white, cracked thallus that appears slightly frosted.
• Other species can be bright yellow with angular aeroles.

Ecological Role

• Lichens, in general, contribute to the breakdown of rocks through slow erosion.

Interactions with Other Organisms

• The text notes instances where lichens grow on trees alongside moss and fungi.
• Scentless mayweed is noted as growing with cracked lichen in one image.

Further Information

• The text refers to resources such as the "Catalogue of Life: 2012 Annual Checklist" and Mushroom Observer.
• It also references a "glossary of British lichens."