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Eggyolk Lichen: A Colorful Symbiosis

Eggyolk lichens are crustose or squamulose lichens that get their name from their distinctive yellow color. They are a fascinating example of symbiosis, a partnership between fungi and algae.

Scientific Name and Common Names

• Genus: Candelariella Müll. Arg.
• Common Names: Eggyolk lichen, goldspeck lichen, yolk lichen
• Species Examples:
  • Candelariella antennaria Räsänen - Pussytoes eggyolk lichen
  • Candelariella aurella - Eggyolk Lichen
  • Candelariella dispersa (Räsänen) Hakul. - Dispersed eggyolk lichen
  • Candelariella terrigena Räsänen - Eggyolk Lichen
  • Candelariella spraguei - Sprague's eggyolk lichen
  • Candelariella deflexa - Deflexed eggyolk lichen
  • Candelariella vitellina - Eggyolk lichen

Taxonomy and Nomenclature

• Family: Candelariaceae
• The text also mentions lichens in the Lecanoraceae family, but it's not directly associated with the Eggyolk Lichen.

Distribution and Habitat

• The Dispersed Eggyolk Lichen is found in the USA, according to the USDA.
• One sample of Candelariella pacifica was found in a spruce plantation with dispersed old maples.
• They can be found on coastal rocks and in lichen-dominated sites with poor soils.

Morphological Characteristics and Growth Habits

• Eggyolk lichens are described as crustose or squamulose.
• The thallus of Candelariella pacifica is formed of egg yolk-yellow squamules to lobes.
• Some species have a weakly formed thallus of dispersed areoles.
• The color is typically egg-yolk yellow, but can also be lemon yellow, strong yellow or chartreuse. The yellow color comes from calycin.

Ecological Role

• Lichens can be found on dead plant stems, leaves or bark and may be found in fumitory bolete mushrooms, lichen, and Iceland moss.

Interactions with Other Organisms

• Eggyolk lichens are a symbiotic relationship between a fungus and a green alga, which is evenly dispersed throughout the interior of the thallus. A secondary photobiont is typically absent.