Miss H.G.D. (Ike)  Zewald was appointed as artist at the Botanical section of the Agricultural University of Wageningen (Netherlands). From the very start of De Wit as professor in botany, she made drawings for the various publications of the institute. As the taxonomic institute was mainly on African plants, the drawings presented here on Cryptocoryne  form only a small part of her work. See her other work at Ike Zewald.  See also the page on de Wit.
All drawings found in the last edition of de Wit's book  (1990) are published here, for a reference to the herbarium specimen used for the drawings see de Wit (1990) on the Document service.

Wit, H.C.D.de, 1990. Aquarienpflanzen, 2. Auflage,Ulmer, Stuttgart.
The drawing  of  C. pallidinervia (C. venemae) is only published in: Wit, H.C.D.de, 1971. Aquarienpflanzen. Ulmer, Stutgart.
The drawing of C. fusca (2) is found in: Wit, H.C.D.de, 1953. Cryptocoryne longicauda Beccari ex Engler. Het Aquarium 23(11) : 248-250.
The drawing C. versteegii (2) is found in: Wit, H.C.D.de, 1958. Slow-growing  Cryptocoryne Species. Fishkeeping, june 1958 : 392-393.
The drawing C. thwaitesii (2) comes from: Wit, H.C.D.de, 1958. A Diminutive Cryptocoryne. Fishkeeping, august 1958 : 488-489.

The drawing of C. pontederiifolia has some parts added by Mrs. Juliet Williamson, who also made the drawing of C. crispatula var. crispatula.
The drawing of C. dewitii is made by Mrs. Marianne Krøjgaard.