Verrucaria

tar lichenTar lichens (Verrucaria nigrescens) on a coastal rock.

Verrucaria, genus of lichens of the family Verrucariaceae, often found as a black crust covering seashore rocks. Along with the effects of weathering, Verrucaria helps break down limestone rocks by secreting acids that dissolve the cement holding together the rock particles. This produces an environment for the growth of mosses and higher plants.

This article was most recently revised and updated by Melissa Petruzzello.
Citation Information
Article Title: Verrucaria
Website Name: Encyclopaedia Britannica
Publisher: Encyclopaedia Britannica, Inc.
Date Published: 31 December 2015
Access Date: March 14, 2025