Many thanks to:
Alan Radcliffe-Smith for allowing us to base this work on his manuscript.
Kehan Harman, Rogier de Kok and Don Kirkup (Royal Botanic Gardens, Kew) for teaching me how to use DELTA and INTKEY. And their ongoing support on building interactive keys.
Susana Baena for providing the map.
The Malesian Key Group (Kew/Leiden) for allowing me to use their character illustrations.
The Malpighiales Team (Royal Botanic Gardens, Kew) for allowing access to the Croton collections.