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Dot Lichen

The term "Dot Lichen" is a common name applied to lichens belonging to the genera Arthonia or Micarea. The term "Dotted lichens" refers to lichens in the genus Bacidia. Several different lichen species also share the common name "Dot Lichen."

Considerations for Pets

• Some Dot Lichens are very small and grow on rocks, which might present a minor ingestion hazard if pets lick or chew on rocks where these lichens are growing.

Nomenclature and Taxonomy

• Group: Lichen
• Family: Arthoniaceae (for Arthonia and related species)
• Family: Icmadophilaceae (for Pink Dot Lichen - Dibaeis absoluta)
• Family: Micareaceae (for Erratic Dot Lichen - Micarea erratica)
• Kingdom: Fungi (Lichens are a symbiotic relationship between fungi and algae or cyanobacteria)
• Phylum: Ascomycota
• Class: Lecanoromycetes
• Order: Lecanorales (for Erratic Dot Lichen - Micarea erratica)

Common Names & Scientific Names:

• Birchbark Dot Lichen: Leptorhaphis epidermidis, Leptorhaphis atomaria
• Orange Dot Lichen: Protoblastenia rupestris
• Hidden Dot Lichen: Japewia tornoensis
• Pink Dot Lichen: Dibaeis absoluta
• City Dot Lichen: Scoliciosporum chlorococcum (Synonym: Bacidia chlorococca)
• Erratic Dot Lichen: Micarea erratica
• Granite Firedot Lichen: Caloplaca arenaria
• Firedot Lichen: Caloplaca holocarpa, Cliostomum griffithii
• Scattered-dot Goldspeck Lichen
• Dispersed Dot Lichen: Arthonia dispersa
• Tuckerman's Dot Lichen: Arthonia tuckermaniana
• Nitschke's Dot Lichen: Micarea nitschkeana
• Six-celled moss-dot: Bilimbia sabuletorum

Distribution and Habitat

• Dot lichens can be found worldwide in diverse environments.
• Mycobilimbia pilularis grows as small dots on rocks.
• Arthonia rubella has been observed growing on palm tree bark in Bahia Honda Key, Florida, USA.
• One of the most abundant lichens in the New Orleans area is a dot lichen that goes unnoticed by most people.
• Lichens have been found growing on the stone walls of the Walden road.

Morphological Characteristics

• Mycobilimbia pilularis is a crustose lichen with a grayish-green thallus. It lacks soredia and isidia and features yellowy-brown biatorine, convex apothecia.
• Dibaeis absoluta (Pink Dot Lichen) features pink apothecia borne on very short (approximately 1 mm) stalks.
• Some dot lichens grow in small dots on rocks.
• Speckled Shield Lichens (Punctelia bolliana) are grey foliose lichen with a few tiny white dots and lots of tiny lobules, but no isidia or soredia.

Ecological Role

• Lichens are symbiotic organisms, representing a partnership between a fungus and an alga or cyanobacterium.

Interactions with Other Organisms

• Dot Lichen can be found on Palm tree bark.

Resources and Further Information

• Encyclopedia of Life
• Catalogue of Life
• USDA
• Smithsonian Institution, National Museum of Natural History, Department of Botany
• ResearchGate
• WikiSpecies