Inside the order, some doubt remains about the position of the entirely mycoheterotrophic family Triuridaceae, since it is the only one on which genetic analyses have not yet been applied. With high probability, the family may be sister to the Velloziaceae, but similarities with the family Zingiberaceae (which is a part of a whole different order – Zingiberales) do not exclude the chance for a different phylogeny. The family Velloziaceae on its own is placed at the base of the tree. The Pandanaceae and Cyclanthaceae are sister groups, and they form a clade which on its own is sister to the Stemonaceae (a family composed of two more clades).