General and Introductory | Lichens of Wales

Frank Dobson's "Illustrated Guide to Lichens" (6th Edition published Oct. 2011) has a very good introductory section covering topics including the fundamental "What is a lichen?" as well as broad outlines of the biology and ecology of lichens, and how to study them. Details are given of the chemicals tests used to aid identification.
More extensive background information is given in Oliver Gilbert's excellent New Naturalists volume "Lichens", with chapters covering uses of lichens, air pollution and lichens, lichen communities, as well as individual habitats in which lichens are important.
Other good introductory texts are "Understanding Lichens" by George Baron (1999) and "Lichens" by William Purvis.
There are a number of booklets and fold-out charts available:
- Lichens on Trees - A Guide to Some of the Commonest Species. A. Orange (1994). National Museum of Wales. Short descriptions of 39 species with photographs and excellent line drawings to illustrate to clarify identification features.
- Lichens of Atlantic Woodlands - 1 & 2. A. Acton and A Griffith (2008). Plantlife Scotland. Two fold-out leaflets with excellent photos and notes on identification. The first deals with lichens on ash, hazel, willow, rowan and old oak; the second with lichens on birch, alder and oak. Available on waterproof paper or as downloads (Guide 1; Guide 2) from the Plantlife website.
- The Field Studies Council publish a number of fold-out guides on water-resistant paper. They include: Rocky shore lichens; lichens of heaths and moors; urban lichens (trees and wood); urban lichens (stone and soil); churchyard lichens; and lichens on twigs.
Online introductory material:
- More about lichens An abridged version of a series of e-learning modules on lichens created by the University of Turin, the University of Trieste, and the Italian Lichen Society as part of the European Key to Nature project.
- A Powerpoint slide presentation by Alan Orange of the National Museum, Wales.