SafePlants

Xanthoria parietina: The Common Orange Lichen

Xanthoria parietina is a foliose (leafy) lichen with a wide distribution, known by several common names. Its vibrant color and prevalence make it a familiar sight in various environments.

Considerations for Pets

• This lichen commonly grows on rocks, concrete, and trees.

Considerations for Children

• Pigments can be extracted by boiling and used to dye wool and other fibers.
• This lichen commonly grows on rocks, concrete, and trees.

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Common Names: Common orange lichen, yellow scale, maritime sunburst lichen, orange lichen, orange wall lichen, golden shield lichen, shore lichen.
• Family: Teloschistaceae
• Xanthoria is a genus of lichenized fungi.
• Synonyms: Xanthoria elegans is mentioned as "elegant sunburst lichen" and likely related but distinct.

Distribution and Habitat

• Xanthoria parietina has a wide distribution and can be found in many locations.
• It grows on rocks, concrete, and trees.
• It can be found near cattle farms, as it favors ammonia.
• Observed locations include the Mount Washburn Trail in Yellowstone National Park, Wyoming, and Humboldt Lagoons State Park, California. Also found in New Zealand coastal rocks.

Morphological Characteristics

• Foliose (leafy) lichen.
• Forms large, rounded patches up to 10 cm across.
• Has wide, round-lipped marginal lobes.
• The thallus (body) is yellowish-green to orange.
• Lacking isidia or soredia; apothecia (fruiting bodies) are usually present.
• Fruiting structure has a dark orange disc surrounded by a lighter edge.

Ecological Role

• Can be especially prolific in certain environments.
• Orange lichens identify hunting perches of birds and grow in profusion in seabird colonies.
• Grows in areas above the salt lichen.

Quirky Facts

• The orange color of this lichen is due to the production of the pigment parietin.
• An orange pigment found in lichens and rhubarb called parietin may have potential as an anti-cancer drug.

Interactions with Other Organisms

• Lichens are a symbiotic association between a fungus and an alga.
• The alga Trentepohlia is seen as a vivid orange powdery deposit on trees.

Further Information

• Microchemical Methods for the Identification of Lichens by Alan Orange is mentioned as a guide for chemical use and precautions.