The book provides a comprehensive overview of current knowledge about "wattles", a large clade of over 1000 species of trees and shrubs in the genus Acacia, most of which are native to Australia. It examines the biology, ecology, evolution, and biogeography of wattles in their native ranges, including the evolutionary forces that have driven past speciation and adaptation to diverse environments, the conservation status, uses and human perceptions of these species. It considers the different histories of the introductions and proliferation of wattles as alien species in different parts of the world since c. 1850 (the Anthropocene), situated within relevant political, socio-economic and scientific contexts, together with an analysis of how awareness of their impacts as invasive species has changed over time. Differences in the dynamics and trends associated with the introduction, naturalization and invasion of wattles in different parts of the world are reviewed. The book also synthesizes the global distribution of wattles using diverse data sources, alongside trends, patterns and projections of global uses of wattles. It discusses the genetics, biotic interactions, and ecological, economic and social impacts of invasive wattles. This book is aimed at academics and students in the field of ecology, and at managers of natural and anthropic ecosystems, policy-makers and regulators, and the general public interested in biology and environmental science.