SafePlants

Xanthoria parietina: The Common Orange Lichen

Xanthoria parietina, a vibrant and widespread lichen, adds a splash of color to various environments. Often referred to as the common orange lichen, this fascinating organism is a testament to the symbiotic relationships found in nature.

Lichens, like Xanthoria parietina, are not single organisms but rather a partnership between a fungus and an alga. This symbiotic relationship allows them to thrive in harsh conditions that neither organism could endure alone.

Common Names

• Common orange lichen
• Yellow scale
• Maritime sunburst lichen
• Orange lichen
• Orange wall lichen
• Sunburst lichen
• Golden Shield Lichen
• Shore Lichen

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Genus: Xanthoria
• Family: Teloschistaceae
• Rank: Species
• Caloplaca Th. Fr.

Considerations for Pets and Children

• The text mentions that pigments from colorful lichens, including orange ones, can be extracted by boiling and used to dye wool and other fibers. While not inherently dangerous, it is important to supervise children and pets to prevent accidental ingestion or contact with dyed materials.

Distribution and Habitat

• Xanthoria parietina has a wide distribution and can be found in various environments, including coastal rocks, trees, concrete, and even tombstones.
• It is also noted that it may be found near cattle farms, as it favors ammonia-rich environments.
• It has been observed in the Western Isles.
• It can be found on rocks at the beach by the edge of the Gyon Bluffs, near Freshwater Lagoon, Humboldt Lagoons State Park, California.
• Common crust-forming lichen of coastal rocks in New Zealand.

Morphological Characteristics and Growth Habits

• Xanthoria parietina is a foliose (leafy) lichen that forms large, rounded patches up to 10 cm across.
• The thallus (body) is typically yellowish-green to orange, but may appear grey in shaded areas.
• It lacks isidia or soredia.
• Apothecia (fruiting bodies) are usually present.

Interactions with Other Organisms

• The text mentions that orange lichens can identify hunting perches of birds and grow in profusion in seabird colonies.

Quirky Facts

• The orange color of Xanthoria parietina is due to the production of the pigment parietin.
• Parietin, the orange pigment found in lichens, may have potential as an anti-cancer drug because it interferes with the development of cancer cells.

Further Information

• Orange, A. 1994. Lichens on Trees. A Guide to Some of the Commonest Species. Series: British Plant Life 3. National Museum of Wales.
• Orange, A. 1998.
• Microchemical Methods for the Identification of Lichens by Alan Orange.