SafePlants

Xanthoria parietina: Common Orange Lichen

Xanthoria parietina, a striking foliose (leafy) lichen, is known by several common names, including common orange lichen, yellow scale, maritime sunburst lichen, orange lichen, and orange wall lichen. Its vibrant color makes it easily recognizable in various environments.

Considerations for Pets

• This lichen 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, sunburst lichen.
• Family: Teloschistaceae
• Xanthoria elegans is a related species, commonly known as the elegant sunburst lichen.
• Caloplaca Th. Fr. is a related lichen with similar characteristics

Distribution and Habitat

• Xanthoria parietina has a wide distribution and is commonly found in coastal areas.
• It grows on rocks, concrete, trees, and tombstones.
• It is also found near cattle farms, as it favors environments rich in ammonia.
• Reported locations include the Western Isles, coastal rocks of New Zealand, Humboldt Lagoons State Park in California, and mountainous areas.

Morphological Characteristics

• It is a foliose lichen, forming large, rounded patches that can reach up to 10 cm across.
• The lobes at the edges are wide and round-lipped.
• The thallus (body) ranges in color from yellowish-green to golden-yellow or orange, and may appear grey in shaded areas.
• It lacks isidia or soredia (asexual reproductive structures).
• Apothecia (fruiting bodies) are usually present, featuring a dark orange disc surrounded by a lighter edge.
• Starts as a small yellow or orange dot and gradually grows from the center, leaving the center white or grey.

Ecological Role and Interactions

• Birds may use Orange lichens to find hunting perches
• It can be found in an orange lichen belt distinguishable below White and Grey.

Quirky Facts

• The orange color of Xanthoria parietina is due to the production of parietin, a pigment that can be extracted by boiling and used to dye wool and other fibers.
• Parietin is being researched for its potential as an anti-cancer drug, due to its ability to interfere with cancer cell processes.

Further Information

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