Langenheim, J.H. Plant resins: chemistry, evolution, ecology and ethnobotany.

Abstract

When I agreed to review this book, I did so because I thought it would be an opportunity to bring myself up‐to‐date in a field I felt I ought to know more about. I had no idea that it would make such compulsive reading. Jean Langenheim has spent her career working on plant resins and she has done a great service by assembling her wealth of knowledge and experience into this marvellous book. The blandness of the title belies the wealth of information contained in its pages. In her preface, Langenheim states that she decided ‘the book should tell the whole story of these fascinating plant substances’. I can only say that she has succeeded in her aim. The book is a real eye‐opener to the fact that we are surrounded in our daily lives by products made from or containing plant resins or compounds derived from them. If you doubted their importance to mankind before reading this book, you won’t afterwards! As botanists we are all familiar with Canada Balsam as a mountant for microscope specimens (the more mature ones among us anyway), but few of us are probably aware of its older uses by native North Americans as ‘an antiseptic salve for sores, cuts and burns and an internal medicine for colds, consumption, menstrual irregularity, as a laxative and for other ills’. As Langenheim demonstrates, the list of uses of resins in folk medicine and pharmacy alone is huge. They have been used since ancient times as anaesthetics, analgesics, anti‐allergens, anti‐carcinogens, antiseptics, antibiotics, antispasmodics and astringents (and these are just some of the uses beginning with ‘a’!). The impression given in the book is that every known human illness has been treated with a resin or resin component by someone, somewhere, sometime. They have also been used as aphrodisiacs, contraceptives, flavourings, fuel, for illumination, incense, jewellery, laxatives, narcotics, ornaments, in paints and varnishes, as perfume fixatives, paper coatings and in floor‐coverings (linoleum), etc. The list is seemingly endless. The chapters are laid out in a logical way, beginning with a clear explanation of exactly what resins are, their structure and chemistry and the numerous plants and parts of plants in which they are produced. This is followed by an account of the formation and geographical distribution of amber deposits, which leads naturally into a discussion of evolution of resin production and resin‐producing plants. The account of the ecological roles of resin and the co‐evolution occurring between plants and insects is particularly fascinating, illustrating, for example, the evolutionary ‘arms race’ between plants and predatory beetles, as well as the way resins are used as construction materials by bees for defence of their hives against bacterial and fungal pathogens. The ethnobotanical section of the book dealing with historical and cultural importance of amber and resins and their uses by indigenous peoples demonstrates the key role played by these substances in the civilization of human beings. It was by trading Baltic amber for metals with more advanced peoples that the Neolithic peoples of the Baltic region were enabled to move out of the Stone Age. The book describes how analysis of traded amber artefacts has been used in archaeology to establish trading patterns and relationships between peoples in the ancient world. An equally thorough treatment is applied to the more recent history of resin in the development of New World countries. Excellent accounts are given of the development of the naval stores trade in America and the trade in copal from Agathis australis in New Zealand. The section on the use of resins by indigenous cultures is fascinating and very relevant at a time when traditional plant remedies are being re‐evaluated for use as pharmaceuticals. A number of useful appendices are included listing resin‐producing plants and their distribution; chemical skeletons of fossil resins; age, location and plant source of amber deposits; common names, plant sources and use of resins, and, importantly for the non‐specialist, a comprehensive glossary. The bibliography runs to 68 pages and there are useful plant and subject indexes. The book is very well‐written and highly readable. It provides a comprehensive account that will appeal to both newcomers to the subject as well as to specialists. There is something here for botanists of all disciplines and for non‐botanists in the fields of archaeology, anthropology, pharmaceutical research, and even the interested layman. Considering the size of the book, the quality of its production and the fact that it contains 24 colour plates in addition to black and white photographs, numerous line drawings, maps and tables, it is hard to believe that the price is so low. The book is not only an excellent work of scholarship, it is also excellent value for money.