Dutch botanist. H.C.D. de Wit is well known for his books on aquarium plants, and particularly for his research into the genera Cryptocoryne (of which he described 21 new species) and Lagenandra (6 new species). His book Aquariumplanten was published in Dutch, German, and English, and illustrated with his own colour photographs and drawings made by Miss Ike Zewald. De Wit also published books on other plants (Fabaceae, Resedaceae, and the grass genus Setaria), produced two volumes on flowering plants, and a three-volume publication in Dutch on the history of biology.

Born in 1909 in Pumerend, the Netherlands, he studied biology at the University of Amsterdam and in 1937 went to Pretoria in South Africa where he worked as a Research Officer in the Department of Agriculture. Gaining his doctoral degree in biology in 1941, he was appointed that year as a botanist at the Botanic Gardens in Boitenzorg (today Kebun Raya Bogor), Java, where he worked on plant taxonomy. Returning to the Netherlands in 1946, he worked as a botanist for the Flora Malesiana Foundation until 1953 when he became a lecturer at the University of Leiden, teaching taxonomy and morphology of angiosperms. He was also appointed that year as a lecturer at the Landbouwhogeschool in Wageningen, and in 1969 became Director of the Laboratory of Plant Taxonomy and Plant Geography until his retirement in 1980. During his years in Wageningen he developed a fine collection of water plants in the greenhouses, including a large collection of Lagenandra and Cryptocoryne, among them a number of new species described from cultivated plants grown there. De Wit is honoured with his name in both of his favourite genera: Cryptocoryne dewitii N. Jacobsen and Lagenandra dewitii Crusio & A. de Graaf.