sentences:  The circumscription of the family is variable, with some systems describing the family as consisting solely of the genus "Sladenia", which has been variously considered a member of the Theaceae, the Actinidiaceae, the Dilleniaceae, or the Ternstroemiaceae.Other systems include the genus "Ficalhoa" and possibly the genus "Pentaphylax" in a family with "Sladenia".Morphological studies of the "Sladenia" embryo suggest it has unique characteristics that merit placing the genus in its own family.