This field guide illustrates and describes ca. 20% of the recorded 1’160 vascular plants of the department of Arequipa in Southern Peru. It aims to be a comprehensive field guide for tourists and locals. The first part of the book describes the vegetation of Arequipa. It gives an overview of the harsh conditions of south-peruvian ecosystems. Bone-dry deserts and high mountains with extreme temperature fluctuations challenges plant growth. Such ecosystmes demand adaptation by the inhabitants, especially by the plants, which can not escape their habitat. The second part of the book is dedicated to the plant species of the departement of Arequipa. With the illustrations and the description in this book, the reader should be able to recognize the plants in their habitat. Additionally it provides information about the use and the ecology of the described species.