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Xanthoria parietina: The Common Orange Lichen

Xanthoria parietina, a vibrant foliose lichen, adds splashes of color to various environments. Often called "common orange lichen," it is a widely distributed species with several other common names that reflect its appearance and habitat.

Considerations for Pets and Children

• Pigments: The text mentions that pigments from colorful lichens, including orange ones, can be extracted by boiling and used to dye wool and other fibers.
• Habitat: This lichen grows on rocks, concrete, and trees, sometimes near cattle farms, suggesting it's commonly found in outdoor environments.

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Common Names: Common orange lichen, yellow scale, maritime sunburst lichen, orange lichen, orange wall lichen, sunburst lichen, golden shield lichen, shore lichen.
• Genus: Xanthoria
• Family: Teloschistaceae
• Xanthoria elegans is also mentioned as commonly known as the elegant sunburst lichen, and Caloplaca luteoalba is the Orange-fruited Elm-lichen.

Distribution and Habitat

• Xanthoria parietina has a wide distribution.
• It grows on rocks, concrete, and trees.
• It can be found near cattle farms, where ammonia is prevalent.
• Common on coastal rocks in New Zealand and California.

Morphological Characteristics

• Xanthoria parietina is a foliose (leafy) lichen.
• It forms large, rounded patches up to 10 cm across.
• The marginal lobes are wide and round-lipped.
• The thallus (body) is yellowish-green to orange.
• Apothecia (fruiting bodies) are usually present.

Ecological Role

• Xanthoria elegans is highly tolerant of certain conditions.
• Orange lichens identify hunting perches of birds.

Interactions with Other Organisms

• Lichens are a symbiotic association between a fungus and an alga.
• Algae, lichens and moss often form green or grey, powdery or mossy, crusty growths.

Quirky Facts

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

Further Information

• Alan Orange's "Microchemical Methods for the Identification of Lichens" is mentioned as a resource.
• National Museum of Wales. Orange, A. 1994. Lichens on Trees. A Guide to Some of the Commonest Species. Series: British Plant Life 3.