 In 2005, an attempt was made to obtain DNA for sequencing from the only known specimen, but this failed.Based on an analysis of the morphology of the specimen, Doust and Stevens suggested that "Haptanthus" was possibly related to the Buxales.The APG III system of 2009 accepted the family Haptanthaceae, placing it in the order Buxales, along with the Buxaceae.