Duplicate networks: the Berlin botanical institutions as a 'clearing house' for colonial plant material, 1891-1920

For centuries, herbarium specimens were the focus of exchange in global botanical networks. The aim was the 'complete' registration of the flora, for which 'complete' collections in botanical institutions worldwide were considered to be a necessary basis, although this ardently sought-after ideal was never achieved. The study of colonial plants became a special priority of botanical research in the metropolises. With knowledge of the many treasures of the plant world considered the key to securing wealth and power, political and economic interests influenced both the organization and the subject matter of scientific research. After the German Reich began annexing colonies in the 1880s, legal regulations established Berlin's botanical institutions as the research centre on colonial flora. They also became a clearing house for plant material from overseas. Berlin-based curators selected duplicates of herbarium specimens from the German colonies, distributing them to other botanical institutions throughout Germany. More importantly, duplicates became a form of currency in trans-imperial networks, which relied on reciprocity. In exchange for duplicate German colonial herbarium specimens, the Berlin institutions received vast quantities of botanical samples from their British, Dutch, French and American counterparts.