SafePlants

Dot Lichen: A World of Tiny Wonders

The term "dot lichen" refers to lichens found within the genera Arthonia or Micarea. However, it's important to note that "dotted lichens" can also refer to lichens belonging to the genus Bacidia, highlighting the complexity of common names in lichen identification.

Taxonomy and Nomenclature

• Group: Lichen
• Family: Arthoniaceae (for some species) and Icmadophilaceae for Pink Dot Lichen (Dibaeis absoluta)
• Rank: Genus (Arthonia, Micarea, Bacidia)
• Synonyms: Several species previously classified under different names now fall under the "dot lichen" umbrella, reflecting ongoing taxonomic revisions. For example, City Dot Lichen (Scoliciosporum chlorococcum) is also known as Bacidia chlorococca.

Distribution and Habitat

• Dot lichens are found globally, including locations such as New Orleans, Florida (Bahia Honda Key), and Mount Rainier National Park, indicating their adaptability to various environments.
• They can be found on diverse substrates, including rocks, tree bark (e.g., palm trees, birchbark), and even man-made structures like stone walls.

Morphological Characteristics

• Dot lichens are characterized by their small, dot-like appearance.
• Mycobilimbia pilularis 'Dot Lichen' is a crustose lichen with a grayish-green thallus and yellowy-brown biatorine, convex apothecia.
• Pink Dot Lichen (DIBAEIS ABSOLUTA) has pink apothecia on short stalks.

Species Examples

• Birchbark Dot Lichen (Leptorhaphis epidermidis and Leptorhaphis atomaria)
• Orange Dot Lichen (Protoblastenia rupestris)
• Hidden Dot Lichen (Japewia tornoensis)
• Pink Dot Lichen (Dibaeis absoluta)
• City Dot Lichen (Scoliciosporum chlorococcum)
• Erratic Dot Lichen (Micarea erratica)
• Dispersed Dot Lichen (Arthonia dispersa)
• Tuckerman's Dot Lichen (Arthonia tuckermaniana)
• Nitschke's Dot Lichen (Micarea nitschkeana)
• Globe Dot Lichen (Micarea globulosella)

Quirky Facts

• Dot lichens can be so inconspicuous that they often go unnoticed, even when abundant.
• Some dot lichens, like the "blazing firedot lichen," exhibit vibrant colors, adding beauty to their often-overlooked world.

Further Resources

• Encyclopedia of Life
• Catalogue of Life
• USDA Plant Database
• Smithsonian Institution, National Museum of Natural History, Department of Botany
• ResearchGate (for Conservation Assessments)
• WikiSpecies