The Haloragaceae ( alternate spelling Halorrhagidaceae) are very diverse in habit, including both small trees and submerged aquatics.

A major circumscription was carried out by Schindler in 1905, dividing the "Halorrhagaceae" into two subfamilies (Halorrhagoideae and Gunneroideae) and the former into two tribes (Halorrhageae and Myriophylleae), with a total of seven genera.

[7] This classification long remained the standard till Shaw (1966) removed Gunnera (into its own family Gunneraceae, within the order Gunnerales), the sole genus in Gunneroideae, leaving six genera.

In addition, Meionectes was reinstated, separating two species from Haloragis and creating a new monotypic genus, Trihaloragis by segregating Gonocarpus hexandrus.

Consequently the number of genera is increased to ten, with the addition of:[3] Glischrocaryon-Haloragodendron is resolved as the basal node, sister to the remaining family.

The terrestrial genera (Glischrocaryon, Gonocarpus, Haloragis, Haloragodendron, Trihaloragis ) are primarily limited to the southern hemisphere.