SafePlants

Xanthoria parietina: Common Orange Lichen

Xanthoria parietina is a foliose lichen known by several common names, including common orange lichen, yellow scale, maritime sunburst lichen, orange lichen, and orange wall lichen.

Considerations for Pets and Children

• Pigments from orange, red, and brown lichens like Xanthoria parietina can be extracted by boiling and used to dye wool and other fibers, indicating potential staining if handled.
• This lichen commonly grows on rocks, concrete, and trees, and may be found near cattle farms, suggesting a potential presence in areas accessible to pets and 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.

Distribution and Habitat

• Xanthoria parietina has a wide distribution.
• It is commonly found on rocks, concrete, and trees.
• It is often observed in coastal areas, on tombstones, and near cattle farms.
• It can be found on rocks at the beach and along bluffs, such as the Gyon Bluffs near Freshwater Lagoon in Humboldt Lagoons State Park, California.
• Observed in the Western Isles, New Zealand.

Morphological Characteristics

• Xanthoria parietina is a foliose (leafy) lichen.
• It forms large, rounded patches up to 10 cm across, with wide, round-lipped marginal lobes.
• The thallus (body) is yellowish-green to golden-yellow or orange, and may appear grey in shade.
• It lacks isidia or soredia.
• Apothecia (fruiting bodies) are usually present, with a dark orange disc surrounded by a lighter edge.
• Some forms start as a small yellow or orange dot and gradually grow outward from the center, eventually leaving the center white or grey.

Ecological Role

• It is highly tolerant of sea environments.
• This lichen favours ammonia rich environments, like those near cattle farms.

Interactions with Other Organisms

• Lichens are a symbiotic association between a fungus and an alga.
• Orange lichens can identify hunting perches of birds.
• Algae, lichens and moss often form green or grey, powdery or mossy, crusty growths on trees.

Quirky Facts

• The orange color of this lichen is due to the production of the pigment parietin.
• Parietin, an orange pigment found in lichens and rhubarb, may have potential as an anti-cancer drug.
• The presence and intensity of the orange color can vary with the amount of sun or rain; shaded lichens may appear green.

Further Information

• Katja Schulz marked "Common orange lichen 3" as trusted on the "Xanthoria parietina" page.
• Microchemical Methods for the Identification of Lichens by Alan Orange is a useful resource.