Biodiversity & Conservation

Tar lichen - Verrucaria maura

Verrucaria maura

Image Adrian Worley - Chthamalus montagui on the black lichen Verrucaria maura. Image width ca 20 cm.
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Distribution map

Verrucaria maura recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

Why do the maps differ?

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Verrucaria maura is not listed under any importance categories.

Taxonomy icon Taxonomy Taxon English term
Phylum Ascomycota Sac fungi
Class Pyrenomycetes
Authority Wahlenberg, 1803
Recent synonyms None
Map icon Recorded Distribution in Britain and Ireland Very common on rocky shores all around the British Isles.
Habitat information icon Habitat information Verrucaria maura is found intertidally on almost all rocky shores except where the rocks are soft and crumbly. It is usually the main constituent of the black band of lichens below a band orange lichens and extends from well above the level of high water down to the zone of mussels and barnacles. The width of the band depends on the wave and tidal exposure of the shore.
Text page icon Description Verrucaria maura is a lichen that forms a thin, matt-black layer on rock surfaces that can resemble an oil stain. Reproductive bodies may be present as tiny black spots. Under magnification the surface is seen to be covered with a mesh of fine cracks that resemble dried mud.
Identifying features
  • An encrusting lichen forming a thin, matt-black coating, up to 1mm thick, on rock surfaces.
  • May cover a large area.
  • Difficult to remove from the rock.
  • The surface appears cracked under magnification.
  • Reproductive bodies, or perithecia, may be present as black dots.
Additional information icon Additional information

This review can be cited as follows:

Penny Avant 2008. Verrucaria maura. Tar lichen. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 09/02/2010]. Available from: <http://www.marlin.ac.uk/speciesinformation.php?speciesID=4572>