This is a good time to look at urban lichens, as levels of sulphur dioxide, air pollution and acid rain have been falling rapidly. Many leafy lichens are growing in sites in central London where they may not have been present for 200 years.
The first urban lichens fold-out chart concentrates on the lichens found growing on trees and wood. The chart is illustrated with 49 colour photographs and includes an easy-to-use visual lichen identification key.
Laminated fold-out chart