Anatomically and morphologically they are reported to have their closest relatives in some species of "Grevillea", then next closest "Hakea"; meanwhile, in 2009 the first step was reported, in the still early studies of their genetics.
Anatomically and morphologically they are reported to have their closest relatives in some species of "Grevillea", then next closest "Hakea", and Dutch botanist Hermann Otto Sleumer included the genus within "Grevillea" in 1939. In 2009 the first step was reported, in the still early studies of their genetics.