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Xanthoria parietina: A Colorful Lichen

Xanthoria parietina, commonly known as common orange lichen, yellow scale, or maritime sunburst lichen, is a vibrant foliose (leafy) lichen species admired for its colorful appearance and widespread distribution.

Considerations for Pets

• This lichen grows on rocks, concrete and trees and may be encountered outdoors.
• Some lichens are known to grow near cattle farms.

Considerations for Children

• Lichens often grow on rocks, including tombstones.
• Brightly colored lichens can be attractive to children.

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Common Names: Common orange lichen, yellow scale, maritime sunburst lichen, orange lichen, orange wall lichen, sunburst lichen
• Family: Teloschistaceae
• Xanthoria is a genus of lichenized fungi.
• Other species in the Xanthoria genus include Xanthoria elegans and Xanthoria polycarpa.

Distribution and Habitat

• Xanthoria parietina has a wide distribution and can be found in various locations, including:
  • Rocks
  • Concrete
  • Trees
  • Coastal rocks (New Zealand)
  • Mountainous areas
  • Western Isles
  • Humboldt Lagoons State Park, California
  • Mount Washburn Trail, Yellowstone National Park, Wyoming
• It's often observed on ridges or edges and can be prolific, especially in areas with high ammonia content, such as near cattle farms.

Morphological Characteristics

• It is a foliose lichen that forms large, rounded patches, growing up to 10 cm across.
• The thallus (body) is typically yellowish-green to golden-yellow or orange, but may appear grey in shade.
• It features wide, round-lipped marginal lobes.
• Fruiting structures (apothecia) are usually present, with a dark orange disc surrounded by a lighter edge.

Interactions with Other Organisms

• It is often found in locations where birds perch.

Quirky Facts

• The orange color of the lichen is due to the production of the pigment parietin.
• The color of lichens can vary with the amount of sun or rain.
• The pigment parietin found in Xanthoria parietina may have potential as an anti-cancer drug.
• Lichens can survive harsh weather conditions that would kill a fungus or an alga growing separately.
• Lichens are sometimes described as "dual organisms" because they are a symbiotic association between a fungus and an alga.

Historical Uses

• Pigments from colorful lichens, including orange ones, can be extracted by boiling and used to dye wool and other fibers.