SafePlants

Xanthoria parietina: The Common Orange Lichen

Xanthoria parietina, a vibrant and widespread lichen, is known by several common names, reflecting its distinctive color and habitat. This foliose lichen adds a splash of color to various surfaces, from rocks and trees to coastal areas.

Considerations for Pets

• The text mentions that Xanthoria parietina can be found growing on rocks, concrete and trees, sometimes near cattle farms. This suggests that it may be present in environments where pets are walked or allowed to roam.
• Some lichens, especially colorful ones, have pigments that can be extracted and used as dyes. While the text does not mention toxicity, it is worth noting the presence of pigments, such as parietin, in this species.

Considerations for Children

• The text mentions that Xanthoria parietina can be found growing on rocks, concrete and trees, suggesting that it may be present in environments where children play or explore.
• Some lichens, especially colorful ones, have pigments that can be extracted and used as dyes. While the text does not mention toxicity, it is worth noting the presence of pigments, such as parietin, in this species.

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Common Names: Common orange lichen, yellow scale, maritime sunburst lichen, orange lichen, orange wall lichen, shore lichen, golden shield lichen.
• Family: Teloschistaceae
• Xanthoria elegans, commonly known as the elegant sunburst lichen, is mentioned as another lichen species.
• Caloplaca Th. Fr. is mentioned and is in the same family Teloschistaceae.

Distribution and Habitat

• Xanthoria parietina has a wide distribution and can be found in various locations.
• It grows on rocks, concrete, and trees.
• It is often found near cattle farms because it favors ammonia.
• Specific locations mentioned include the Western Isles, New Zealand (coastal rocks), Mount Washburn Trail in Yellowstone National Park, and Humboldt Lagoons State Park, California.
• It can be found near the sea, above the salt lichen line.

Morphological Characteristics

• Xanthoria parietina is a foliose lichen, meaning it has a leafy structure.
• It forms large, rounded patches that can grow up to 10 cm across.
• The thallus (lichen body) is yellowish-green to orange, or grey in the shade.
• It lacks isidia or soredia (reproductive structures).
• Apothecia (fruiting bodies) are usually present, featuring a dark orange disc surrounded by a lighter edge.
• The lobes are wide and round-lipped.

Quirky Facts

• The orange color of Xanthoria parietina is due to the production of the pigment parietin.
• The lichen is found in areas with bird perches.

Interactions with Other Organisms

• Lichens like Xanthoria parietina are a symbiotic association between a fungus and an alga.
• It may be found growing with Flavoparmelia caperata on shrubs or Xanthoria polycarpa on the bark of a black oak .
• Orange lichens also identify hunting perches of birds.

Potential Uses

• Pigments from colorful lichens, including orange ones, can be extracted and used to dye wool and other fibers.
• Parietin, the orange pigment in Xanthoria parietina, is being investigated for its potential as an anti-cancer drug.

Additional Resources

• Microchemical Methods for the Identification of Lichens by Alan Orange is mentioned.