[4] Two staminate flowers from the original specimen were re-examined by Andrew Doust and Peter Stevens.

The first is that the staminate flowers are basically as described by Goldberg and Nelson, except there are two stamens with fused or closely pressed filaments and anthers rather than one.

Based on an analysis of the morphology of the specimen, Doust and Stevens suggested that Haptanthus was possibly related to the Buxales.

[5] The APG III system of 2009 accepted the family Haptanthaceae, placing it in the order Buxales, along with the Buxaceae.

[7] The close relationship with the Buxaceae was confirmed in 2011 when DNA was successfully obtained from a newly collected specimen.

[8] Haptanthus hazlettii has only been found in a very small area of tropical rain forest on the northern coast of Honduras, close to Matarras in the Arizona Municipality.

[4] After the original specimen was collected in 1989, numerous attempts were made to find the species again but without success; the area had become covered with grass following tree clearance.

[5] In 2010 an expedition organized by Alexey B. Shipunov and Ekaterina Shipunova found a single tree 2 km (1.2 mi) from the original collection point.