The purpose of this book is to present alphabetically a brief description of economic plants in their broadest sense, with their geographical distribution, their products and principal uses. Such a comprehensive work has long been needed. However, there are a number of useful publications which describe economic plans from certain areas, countries, plant families, genera or economic groups, such as those producing oils, rubber, drugs, spices, essential oils, gums, resins, and so on. These publications have paved the way to a considerable extent for the preparation of this book. Many of these treatises are listed at the end of this work under Bibliography. Crops have been considered that are of importance to agriculture, forestry, fruit and vegetable growing, and pharmacognosy, also those that are of importance to the world trade, as well as plants that are strictly of local value. A considerable number of species are given that are of ethnological interest in that they furnish food, medicine and other commodities of value in the daily life of primitive peoples. Many plants have been included that have proven to be of value in times of want, during wartime, or in certain countries during periods of famine. Over 6000 species have been considered, including the lower as well as the higher forms of plants. A number of species could not be included because the sources were not reliable or important data were uncertain.