Thiele and Ladiges' arrangement remained current only until 1999, when George's treatment of the genus for the Flora of Australia series of monographs was published. This was essentially a revision of George's 1981 arrangement, which took into account some of Thiele and Ladiges' data, but rejected their overall arrangement.
Thiele and Ladiges' arrangement was current until 1999 when George updated it for the Flora of Australia series. This update was based on George's earlier work in 1981, which included some data from Thiele and Ladiges but did not adopt their overall structure.