Introduction Human beings have an affinity for trees. They inspire us, wherever we live. In cities they soften the urban landscape and help to keep us in tune with the changing seasons. Trees are an integral part of the rural environment and, even in regions where they are not, we plant them around our dwellings for shelter, fuel, timber, and their fruits. Particular trees are identified with different areas: the Chestnuts and Elms of the northeastern United States, the Redwoods of California, the Live Oaks of the South, to the conifers of the old growth forests of the Pacific Northwest. England is synonymous with its Oak, the Mediterranean with its olive groves and cypresses. This authoritative volume gives insight into the huge diversity of trees. In fact, in the twenty-first century, we are surrounded by an unnatural diversity as numerous tree species have been introduced from around the world, greatly enriching our natural and manmade environments. Our relationship with trees is an enduring one, though that with forests has changed since earlier generations. Where they saw the frontier wilderness of Jack London and James Fenimore Cooper, or the green hell of the unrelenting jungle, we see forests under threat from logging, pollution, or climate change. Trees now need our help to survive -- but the story is by no means uniformly bleak. The Gingko, or Maidenhair Tree, the Dawn Redwood, and the Wollemi Pine are remnants of the great gymnosperm forests of the Mesozoic Era, home of the dinosaurs. Over the millennia, as new trees evolved, they dwindled to tiny populations on the edge of extinction. Rediscovered and rescued by humankind, they have been brought into cultivation, and quite literally given a new lease of life. Here the message is one of hope -- if we value trees we will look after them, and their descendants will be alive for our descendants to enjoy Colin Pendry B.Sc., Ph.D. Tropical Forest Botanist, Royal Botanic Garden Edinburgh, Scotland. How the Encyclopedia is Organized The material comprises main text, illustrations, tables to aid species identification, fact boxes for a summary of the most important genera, and a thumbnail map showing their native distribution. Species, distribution, diagnostic features of the genus, horticultural and economic importance. and any specific information relevant to that genus are detailed in the text. The tables list all the species of the genus (save in the case of larger genera where main species only are detailed) and give concise facts on common names. distribution, species diagnostic features, and details of their horticultural or economic importance. Wherever possible, the species in each table are divided into natural divisions Subgenus, Section, Series, etc). If no such natural division is available, but species can be grouped, the general terms Group I, II, III... are used. In some cases an entire table or parts of it have been constructed in the form of a key, coded by letter. Thus the first keyed entries will be under A , with the alternative AA and even AAA . Further keyed items work through the alphabet: B , BB ; C , CC , etc. For dimensions of, for example, a leaf it is often necessary to show the normal parameters and extremes that may be found reasonably often; thus (4)5-6(6.7) in ((10)12-l5(17) cm) indicates normal dimensions of 5-6 in (12-15 cm) but with common extremes of as little as 4 in (10 cm) or as much as 6.7 in (17 cm). Many taxonomic changes have taken place over the past 20 years. New discoveries in the field, and further herbarium studies of specimens have led to the reclassification of many families and genera. To reflect these changes, the system of arrangement based on that of G.L. Stebbins in his Flowering Plants -- Evolution Above Species Level , has largely been followed. However, where appropriate, it has been amended and updated according to the system of classification used by D.J. Mabberley in The Plant-Book (2nd edn), the most comprehensive modern treatment covering all groups of plants. In all but the Trees of the Tropics chapter (which is alphabetical by genus), families are arranged in evolutionary order. Climate Zones For each genus, and its main species, the relevant climate Zone(s) in which it grows are represented at the end of the entry by the abbreviation cz . The numbers link the distribution of a genus or species to the climate zone maps of North America and Europe on page 39, following the ten climate zones identified by the US Department of Agriculture. No climate zone figures are included, however, in the section "Trees of the Tropics," since all tropical regions encompass climate zones 9-10, making allowance for local variations in microclimates in tropical mountainous regions where, at altitude, local climate zones may be lower or cooler over relatively small areas. How the Classification Works All entries are ordered by family (with the exception of the "Trees of the Tropics" genera, which are ordered alphabetically). The example below shows how different typography is used to distinguish the names [note: typography has not been preserved in this excerpt]: SALICACEAE [Family name in small caps] Salix [Latin genus in italics] Willows, Salix, Osiers [Common name as main header] The family name appears in small capital letters. Each entry is then shown by its Latin name the genus, identified by italic type) and its common name Most trees have a number of popular or common names of which as many alternatives as possible are included. These are shown prominently in bold type. With regard to the scientific name or binomial there should of course be just one correct name -- this is shown in italic. However, it is often not quite so straightforward since historically several names have been applied to a single species. Here, the system adopted is to use the currently accepted scientific name, as far as is possible, throughout an entry but at first mention other synonyms are given, either in parentheses or by using the = sign. Throughout this work, scientific terminology has been kept to a minimum, but inevitably some has had to be used for the sake of conciseness. For this reason there is a comprehensive Glossary at the end of the book, and the section "What is a Tree?" should be consulted for an account of the structure, reproduction, and growth of trees. Excerpted from Firefly Encyclopedia of Trees All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.