This work investigates the biological and environmental mechanisms that cause seemingly benign garden plants or non-native species to transform into aggressive, invasive weeds. Sir Edward Salisbury, a distinguished botanist and former Director of the Royal Botanic Gardens, Kew, utilizes his extensive field observations and ecological expertise to analyze the life cycles and survival strategies of various plant species. He presents a framework that examines how human-altered landscapes and specific environmental conditions facilitate the rapid spread of these opportunistic organisms.

This text is regarded as a foundational study in the field of weed ecology, reflecting the author's deep expertise in plant biology. The writing provides a dense, scholarly examination of botanical behavior that remains relevant for those interested in the historical development of ecological science.