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Xanthoria parietina: The Common Orange Lichen

Xanthoria parietina is a foliose lichen known for its vibrant color and wide distribution. Often found on rocks, concrete, and trees, this lichen adds a splash of color to various environments.

Common Names

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

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Genus: Xanthoria
• Family: Teloschistaceae
• Another lichen in the same family: Caloplaca

Distribution and Habitat

• Xanthoria parietina has a wide distribution and can be found in various locations.
• It commonly grows on rocks, concrete, and trees.
• It can also be found near cattle farms, as it favors environments with ammonia.
• Observed on the Western Isles, New Zealand, and at Humboldt Lagoons State Park, California.

Morphological Characteristics

• It is a foliose (leafy) lichen forming large, rounded patches that can grow up to 10 cm across.
• The thallus (body) is typically yellowish-green to orange, but may appear grey in shaded areas.
• The fruiting structure has a dark orange disc surrounded by a lighter edge.
• It lacks isidia or soredia.

Considerations for Pets

• This lichen grows on rocks, concrete and trees which pets may interact with.

Considerations for Children

• This lichen grows on rocks, concrete and trees which children may interact with.

Ecological Role

• Xanthoria parietina can be prolific in certain environments, such as below White and Grey lichens, forming an orange lichen belt.
• It is highly tolerant to various conditions, including those near seabird colonies.

Interactions with Other Organisms

• Lichens, including Xanthoria parietina, are formed from a symbiotic association between a fungus and an alga.
• The alga (e.g. Trentepohlia) is contained within the hyphae of the fungus.
• Orange lichens can identify hunting perches of birds.

Traditional Uses

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

Quirky Facts

• The orange color of Xanthoria parietina is due to the production of the pigment parietin.
• Parietin, found in this lichen and rhubarb, is being researched for its potential as an anti-cancer drug.
• Some animals are known for their preference for areas with splashes of orange thalli (lichen bodies).

Further Information

• Information can be found on the &quotXanthoria parietina&quot page.
• Microchemical Methods for the Identification of Lichens by Alan Orange
• Lichens on Trees. A Guide to Some of the Commonest Species. Series: British Plant Life 3. National Museum of Wales. Orange, A. 1998.