 In 1988 Gordon Guymer of the Queensland Herbarium published a taxonomic revision of Brachychiton; he classified B. rupestris in the section Delabechea along with the related and newly described Proserpine bottle tree. A third species, from southeast Queensland, has been recognised but not yet described. Unique to the section, all three species have bulbous trunks and can have large cavities in the vertical wood parenchyma. The genus Brachychiton lies within an Australasian clade within the subfamily Sterculioideae (previously family Sterculiaceae) in a large broadly defined Malvaceae. It is only distantly related to Sterculia, belonging to a different clade within the Sterculioideae.
