About 1% of flowering plants are parasitic, meaning they steal food from other plants, their so-called hosts. The evolutionary origins of parasitic plants remained obscure for centuries. This is because the shift to parasitism was associated with a degeneration of features traditionally used in plant classification, such as leaves. We are interested in the processes by which these parasitic plants may form new species. Our research, pioneered at the University of Bristol, shows that shifting hosts may be a driver of the formation of new species of parasitic plants. Linked to this research, we are planning to develop a unique collection of parasitic plants here in the Garden.