The latest, eagerly anticipated volume of Scandinavian macrolichens is devoted to the Parmeliaceae. It follows very closely the style established in previous volumes. It is a multi-authored work involving 13 contributors, two of whom are based outside Scandinavia.
The Nordic countries are taken to include Denmark, Sweden, Norway, Finland and the islands Iceland, Faroe, Jan Meyen, diminutive Bear Island and ice-capped Svalbard. The geographical coverage lies between latitude 55°N to over 80°N an extension of about 3000 km, with climates ranging from cool-temperate to arctic, seaside to alpine and continental to oceanic. World-wide the Parmeliaceae is the largest family, comprising some 2300 species and 80 genera; almost one-sixth of all known lichens. In the Nordic countries only 152 species occur, in 41 genera, but members of the family are the dominant macrolichens in northern boreal forests.
The introduction is very short, of only three pages, and is confined to a synopsis of the family characteristics. Formerly the Parmeliaceae was dominated by mainly three genera, Parmelia, Cetraria and Usnea. But, the introduction tells us, since the 1960's advances in knowledge of cortical anatomy, secondary chemistry and reproductive structures have led to a greatly expanded phylogeny, additionally based on DNA sequences. Over that period the number of genera included in the family has increased from 18 to about 90 by the 1990s, but there has been a slight decrease since. Nomenclature followed by the authors is the most recent position, despite rapidly occurring changes in species delimitation. The family is treated as monophyletic, and includes predominantly foliose and fruticose species, with a few crustose Xanthoparmelia in the S. Hemisphere and one parasitic genus, Nesolechia. There are two clades in the Parmeliaceae; the Alectorioid and the Parmelioid. The former includes the previously known Alectoriaceae, Cetrariaceae, Hypogymniaceae and Usneaceae. So, as well as the familiar ‘Parmelioids’ we find also in this book, Bryoria, Cornicularia, Evernia, Cetraria, Usnea and so on.
A key to genera occupies almost three pages (double-columns), and they take us to some species names directly. Brief generic descriptions follow, then those for the species, also brief, with single-sentence synopses covering morphology and chemistry. The body of the text is almost entirely in double-columns, usually with 2–3 species per page, and an adequately sized thumbnail distribution map (38×48 mm). A large map (p. 9) shows the abbreviations for provinces and states alluded-to in the descriptions. The write up is brief but thorough. Occasionally extra species are slipped in for completion, for example Allantoparmelia almquistii (Vain.) Essl., is known only outside Scandinavia, from Arctic Russia, Greenland and N. America. This may be a hint for readers to look out for it. The book concludes with 2.5 pages of ‘nomenclatural novelties’ including Latin diagnoses. A list of herbarium label data is given for all species. There is no separate bibliography since all references are given as they occur in text.
For many, the photographs will be a chief attraction. There are 30 pages of them covering every species. They are standardized at 8×6 cm, six per page, all of herbarium specimens, and nearly all against a black background. Most are printed at life-size, with some finer thalli appropriately magnified by up to ×10. Sizes are quite adequate for identification, but many have reproduced in my copy as very dark. This can be rectified by looking at the CD-ROM when our computers can increase brightness and employ zoom for finer details. The 296 jpeg's give mostly several pictures of each species in addition to the single one in the book. They are generously sized, at around 1-2·5 Mb. Generally, all fine details, pseudocyphellae, etc., can be seen without difficulty, and these rather beautiful photographs are a great improvement over the printed versions. The Usnea photographs deserve special mention as there are six for each species, and four taxa per page. Three detail gross morphology, isidia, fibrils, etc, while a further three are of holdfasts, medullary longitudinal sections and finer details. A variety of morphological forms is also given where appropriate.
The hardback version is stoutly bound and seems designed to last. While the text and introduction are brief, they are pertinent to the task of communicating sufficient details to allow the reader to compare their own specimens. Editing and production standards are, as usual with the Nordic Lichen Flora, first-rate.
