SafePlants

Xanthoria parietina: Common Orange Lichen

Xanthoria parietina, a foliose (leafy) lichen, is known by several common names, including common orange lichen, yellow scale, maritime sunburst lichen, and orange wall lichen. Other species mentioned include Xanthoria elegans, commonly known as the elegant sunburst lichen, Xanthoria polycarpa (Pincushion Orange Lichen), and Xanthoria ligulata. The Orange-fruited elm-lichen is also mentioned in the text.

Considerations for Pets

• This lichen commonly grows on rocks, concrete, and trees, locations which dogs may frequent.

Considerations for Children

• This lichen commonly grows on rocks, concrete, and trees, locations which children may frequent.

Taxonomy and Nomenclature

• Scientific Name: Xanthoria parietina
• Family: Teloschistaceae
• Rank: Genus (Xanthoria)

Distribution and Habitat

• Xanthoria parietina has a wide distribution.
• It is often found on rocks, concrete, and trees.
• It is commonly found near cattle farms, as it favors ammonia.
• It can be especially prolific in certain environments.
• In New Zealand, lichens are found in many types of land, from coast to summit.

Morphology and Growth Habits

• Xanthoria parietina is a foliose lichen, forming large, rounded patches up to 10 cm across.
• It features wide, round-lipped marginal lobes.
• The thallus (body) is yellowish-green to orange, and may be grey in shade.
• The fruiting structure has a dark orange disc surrounded by a lighter edge.
• It lacks isidia or soredia apothecia.

Quirky Facts

• Pigments from orange lichens, like Xanthoria parietina, can be extracted by boiling and used to dye wool and other fibers.
• Xanthoria elegans (elegant sunburst lichen) is highly tolerant of bird droppings and often grows in profusion on seabird perches.
• The orange color of this lichen is due to the production of the pigment parietin.

Ecological Role

• Lichens, including Xanthoria parietina, are described as "dual organisms" due to their symbiotic association between a fungus and an alga.
• The alga is contained within the hyphae, allowing the lichen to survive harsh weather conditions.

Interactions with Other Organisms

• The alga Trentepohlia is often seen as a vivid orange powdery deposit on trees.
• Xanthoria elegans is often found on hunting perches of birds.

Potential Uses

• Parietin, an orange pigment found in lichens like Xanthoria parietina, may have potential as an anti-cancer drug.

Further Information

• For detailed information on identifying lichens, refer to Microchemical Methods for the Identification of Lichens by Alan Orange.