Orange Sunburst Lichen

Scientific name - Xantoria elegans

The vivid orange patches on this elm bark belong to Orange Sunburst Lichen (Xanthoria elegans), one of the most striking crustose lichens found across Minnesota. Its bright pigmentation is caused by parietin, a compound that protects the lichen from intense sunlight and UV radiation.

This species is common on exposed bark, rocks, and sometimes even metal surfaces. It often grows alongside foliose lichens such as Flavoparmelia caperata, creating colorful communities on mature trees.

Identification

• Color: Yellow orange, orange. A little greenish orange but not usually.
• Form: Circular leaf-like pattern with branching lobes.
• Form: Crustose (flat, tightly attached to surface) with small lobed edges.
• Surface: Smooth or slightly granular with occasional disk-like fruiting bodies.
• Substrate: Typically found on bark, rock, or wood in sunny conditions.
• Pigment: Contains parietin, giving its vivid orange color and UV protection.

Photos

*Xanthoria elegans growing near greenshield lichens on elm bark in southern Minnesota.

Habitat

Observed on elm bark within a mixed hardwood stand. This lichen prefers sun-exposed bark and is more tolerant of dry, open conditions than many green foliose species. It often colonizes older or partially exfoliating bark, where moisture collects briefly after rain.

Field Notes

• Date: October 24, 2025
• Location: Near Lakeville, MN
• Weather: Cool and sunny — ideal for photographing lichens.

Fun Fact

The pigment parietin not only gives Xanthoria elegans its brilliant hue but also acts as a natural sunscreen. This adaptation allows it to survive in extreme environments — even on Arctic rocks and exposed alpine cliffs.

See also: Common Greenshield Lichen
See also: Minnesota Lichen Guide

References

[Orange Sunburst Lichens, Missouri Department of Conservation] https://mdc.mo.gov/discover-nature/field-guide/orange-sunburst-lichens-xanthoria-lichens