290

BOOK REVIEWS

© 2007 The Linnean Society of London,

Botanical Journal of the Linnean Society,

2007,

154

, 289–290

Blackwell Publishing LtdOxford, UKBOJBotanical Journal of the Linnean Society0024-40742007 The Linnean Society of London? 20071542289290Book Review

BOOK REVIEWS

BOOK REVIEWS

Lichens: An Illustrated Guide to the British and IrishSpecies (5th edition)

by Frank Dobson. Slough: TheRichmond Publishing Co. Ltd, 2005. 480 pp. Colourphotographs and range maps. ISBN 08554 6096 2(paperback); ISBN 08554 6095 4 (hardback). £35.00(paperback) or £45.00 (hardback)

+

postage and han-dling. Available from: rpc@richmond.co.uk.

Frank Dobson has once again improved and updatedhis nearly perfect, nearly pocket-sized guide to Britishlichens. The British Lichen Society, of which Dobson isa long-standing active member, was an importantsource of information and inspiration for this new,fifth edition. It includes about 850 of the most commonBritish lichens (130 more than the previous edition) –roughly half of the entire British lichen flora.

Armed with excellent introductory chapters, colourphotographs, anatomical/spore illustrations, and spe-cies range maps, Dobson draws in the amateurlichenologist whilst holding the attention of the expe-rienced lichenologist. In comparison, Purvis

et al

.’s(1992) landmark

The Lichen Flora of Great Britainand Ireland (

also currently under revision) is meantfor professional lichenologists; indeed, the two bookscomplement each other very nicely. New features ofthe fifth edition include: improved photographs; anexpanded lateral key to genera, including an extensive‘sterile’ section; and a synopsis of each genus (which,as in Purvis

et al

.’s

Flora

, can be very helpful for boththe serious student and professional).

Recent studies indicate that the British lichen florais responding rapidly to changes in land use; air pol-lution patterns; and climate change. Unfortunately, asa result, the relative ‘sulphur dioxide tolerance’ levelsgiven for many of the species in this book are quickly

becoming obsolete, as nitrogen-containing pollutantsbecome more important than sulphur dioxide. Perhapsrelative ‘nitrogen tolerance’ levels should be includedfor some species as well? In addition, the species rangemaps given in the book are inadequate for indicatingshifts in the geographical distributions that reflect theland use and air pollution changes. For example, therange of

Lecanora conizaeoides

in Great Britain hasgreatly decreased over the past 50 years, as coalburning has declined. The range map for this species,however, – which is based on historic specimen records– shows that this species occurs everywhere. Althoughthis misinterpretation is corrected by the text, TheBritish Lichen Society needs to devise a lichen map-ping scheme that reflects changes in distribution overtime. I have no doubt that they will eventually do this,and set a new ‘lichenological standard’ as they have,time and again, in the past.

Unlike Purvis

et al

.’s (1992)

Flora

, Dobson’s bookdoes not mention the worldwide distribution of thespecies included in it, which limits its relevance forbotanists in other parts of the world. Dobson’s book,however, does include many widespread species(e.g.

Alectoria ochroleuca

,

Evernia prunastri

,

Lecanorapulicaris

,

Parmelia sulcata

,

Physcia adscendens

,

Platismatia glauca

) common to other, cool temperatecountries, which makes this an important resource ofcomparative information.

S

COTT

L

A

G

RECA

REFERENCE

Purvis OW, COPPINS BJ, Hawksworth DL, JAMES PW,Moore DM, eds. 1992.

The Lichen Flora of Great Britainand Ireland

. London: The Natural History Museum.