Willem Marius Docters van Leeuwen

Willem Marius Docters van Leeuwen (16 March 1880 – 25 February 1960) was a Dutch botanist and entomologist who worked in the Dutch colony in Indonesia, where he was prominent for conducting studies on insect–plant interactions as well as for his long-term studies on the island of Krakatoa.

Van Leeuwen was born in Batavia, Indonesia and was educated at the University of Amsterdam.

He went to Salatiga, Central Java as an entomologist in 1908 and was also a school teacher in Semarang and later Bandung.

He studied galls, ant–plant symbioses, pollination biology, montane flora and floral succession on the islands of Krakatoa over the course of a long period.

He served as a professor of tropical biology at the University of Amsterdam from 1942 to 1950, where he was popularly known as "uncle doc".