A family of 17 genera and about 600-650 species widely distributed in the warmer parts of the world particularly in North America; five genera occur naturally in Australia.

Ludwigia - A genus of about 75-80 species, widespread throughout the world; four species occur naturally in Australia and two or three species have become naturalised. Raven (1977); Thompson (1990).

Raven, P.H. (1977). Onagraceae. In 'Flora Malesiana.' Ser. 1, Vol. 8, (Noordhoff International Publishing: Leyden.), pp. 98-113.

Thompson, J. (1990). Onagraceae. In 'Flora of Australia.' Vol. 18, (Australian Government Publishing Service: Canberra.), pp. 215-243.