{{Short description, Morphological structure found in some lichens Peltigera_leucophlebia-4

Cephalodia (singular cephalodium) are small gall-like structures found in some species of

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

l symbionts. Cephalodia can occur within the tissues of the lichen, or on its upper or lower surface. Lichens that have both green algal and cyanobacterial symbionts restrict the cyanobacteria to cephalodia. Lichens that have only cyanobacterial symbionts do not have cephalodia: instead the cyanobacteria are widely distributed throughout the lichen. Lichens with cephalodia can fix nitrogen, and can be an important contributor of nitrogen to the ecosystem.

References

*Brodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. Lichens of North America. Yale University Press: New Haven. Lichens Fungal morphology and anatomy