Prof.dr. Peter van Welzen (Naturalis Biodiversity Center and Leiden University) is a taxonomist and biogeographer working on the flora of the Malesian area (Flora Malesiana Project: https://floramalesiana.org/new/). Taxonomically, he specialises, together with other experts, on the family Euphorbiaceae, the spurges (http://www.nationaalherbarium.nl/Euphorbs/). Biogeographically, his research focuses on the origin of the Malesian flora, where did it originate, which dispersal paths were followed, but also which dispersal paths will still be available in the future for migration due to climate change. He has cooperated for already decades with Herbarium Bogoriense and other Indonesian institutes in describing plants from various families.