This is the first introductory book written specifically on Ireland's lichens. Lichen identification is a challenging activity requiring an accurate understanding of lichen anatomy and biology and the associated terminology. Once mastered, a world of Lilliputian biodiversity opens up, using a simple hand lens and this book. Part I describes with accurate line drawings the essential features of lichen anatomy. This is followed with guidelines on how to equip oneself for a comfortable and rewarding outing, maintaining a field notebook, collecting specimens and dissecting them for identification. Finally Ireland's habitats are classified and described with the new lichenologist in mind. Part II describes in pictures and brief accurate text over 200 lichens found specifically in Ireland's landscape. Each description includes a distribution map, appropriate spot test results, spore size and notes on the habitat/substrate that the lichen is most likely to occupy.