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Dot Lichen: A Diverse Group of Lichens

The common name "Dot Lichen" refers to lichens belonging to the genera Arthonia or Micarea. The term "Dotted lichens" is associated with lichens in the genus Bacidia.

Taxonomy and Nomenclature

• Kingdom: Fungi
• Phylum: Ascomycota
• Class: Lecanoromycetes
• Order: Lecanorales (for some species, like Micarea erratica)
• Family: Arthoniaceae (for genera like Arthonia) or Micareaceae (for some species of Micarea) or Icmadophilaceae (for Dibaeis absoluta)

Examples of Dot Lichen Species

• Arthonia arthonioides
• Arthonia asteriscus
• Arthonia exilis
• Arthonia glebosa
• Arthonia dispersa
• Arthonia tuckermaniana
• Micarea nitschkeana
• Micarea erratica
• Mycobilimbia pilularis
• Dibaeis absoluta (Pink Dot Lichen)

Distribution and Habitat

Dot lichens can be found in various locations, including:

• New Orleans area (as noted by Bob Thomas)
• Mount Rainier National Park (growing on rocks)
• Bahia Honda Key, Florida, USA (Arthonia rubella on palm tree bark)

Morphological Characteristics

• Mycobilimbia pilularis ("Dot Lichen") is a crustose lichen with a grayish green thallus, lacking soredia or isidia, and has yellowy brown biatorine, convex apothecia.
• Dibaeis absoluta (Pink Dot Lichen) features pink apothecia born on very short stalks (approximately 1 mm).
• Some dot lichens grow in small dots on rocks.
• Punctelia bolliana is a grey foliose lichen with tiny white dots and lobules.

Resources and Further Information

• Encyclopedia of Life
• Catalogue of Life: 2012 Annual Checklist
• USDA
• Smithsonian Institution, National Museum of Natural History, Department of Botany
• ResearchGate (for Conservation Assessment of Pink Dot Lichen)

Quirky Facts

• Some dot lichen names include descriptive terms such as "firedot," "jewel," "candle flame," "yolk," "goldspeck," and "mottled."