A genus of lichens in which the thallus is crustose, sometimes with radiating lobes. The apothecia are characteristically lecanorine. There are many species, found in a wide range of habitats. Some species are more resistant than most lichens to atmospheric pollution. L. conizaeoides is one of the lichens most tolerant of pollution; this species forms greyish-green, granular crusts on bark, wood, rocks, walls, and the like, even within large cities, but is uncommon in areas with clean air.
Subjects: Plant Sciences and Forestry.