See text Proserpinaca, commonly called mermaidweed,[1] is a genus of flowering plants in the watermilfoil family (Haloragaceae).

It is a small genus, comprising only two to three extant species, all of which are native to eastern North America and the West Indies.

[2] Proserpinaca can be distinguished from its relative Myriophyllum by having 3 stamens and carpels per flower (as opposed to having 4 or 8).

They are:[2] 15 fossil fruits of †Proserpinaca ervinii from the early Miocene, have been found in the Kristina Mine at Hrádek nad Nisou in North Bohemia, the Czech Republic.

[3] Two fossil fruits of †Proserpinaca previcarpa have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark.