This long-awaited book is more than a key volume in the New Naturalist series: it is a work of the first importance by the leading authority on the subject. For though Sir Edward Salisbury is best known to the public for his thirteen years' work as Director of Kew, and for his outstandingly successful gardening books, he has accumulated over years of study a first-hand knowledge of our weed flora that is certainly unique. While it is completely up-to-date, Weeds and Aliens is the result of half a century of observation and curiosity; it is likely to remain for a long time to come a standard work for botanists, farmers, gardeners and naturalists alike. The prime interest of many of us in weeds is how to get rid of them, and for different species in different conditions Sir Edward gives the modern methods of weed control - a subject that has been revolutionised in recent years by the discovery of selective weed-killers. But the scope of the book extends far beyond this practical business of control. How and why a well-managed garden plant or an introduction from abroad will suddenly become an aggressive weed, the history and geography of British weed flora and effects on them of social or agricultural changes, the distribution of weed seeds - by birds or aeroplanes, in grain cargoes or trouser turn-ups - every aspect is fully and clearly explained, with the biological peculiarities of the different species always in mind. The book is illustrated with photographs and with Sir Edward's own line drawings. The idea that because weeds are a nuisance they mist also be dull is dispelled in a few pages. Not only does the author show that an understanding of these criminals of the plant world will make their control both easier and more interesting: he also imparts to the reader something of his own delight and wonder - which is, after all, the principal aim of this series.