Numerous phylogenetic studies have revealed that Sterculiaceae, Tiliaceae and Bombacaceae as traditionally defined are cladisticallypolyphyletic. The APG and APG II systems unite Bombacaceae, Malvaceae sensu stricto, Sterculiaceae and Tiliaceae into a more widely circumscribed Malvaceae, i.e., Malvaceae sensu lato. In that view the taxa formerly classified in Sterculiaceae are treated in the subfamilies Byttnerioideae, Dombeyoideae, Helicteroideae and Sterculioideae of the Malvaceae sensu lato. The Thorne system takes an intermediate approach in combining the bulk of the traditional Sterculiaceae (but not including Sterculia itself) with elements of the traditional Tiliaceae to form the family Byttneriaceae.
Sterculiaceae had previously been recognized as a family by most systematists; in its traditional sense the family includes about 70 genera, totalling around 1,500 species of tropical trees and shrubs. The most famous products of the family are chocolate and cocoa from Theobroma cacao, followed by kola nuts. Many species yield timber.
A 2006 molecular study indicated the Sterculioideae was most likely to be a monophyletic group, and that it had four major clades within it. However, the relationships between the clades were not resolved.[1]
^Wilkie, Peter; Clark, Alexandra; Pennington, R. Toby; Cheek, Martin; Bayer, Clemens; Wilcock, Chris C. (2006). "Phylogenetic Relationships within the Subfamily Sterculioideae (Malvaceae/Sterculiaceae-Sterculieae) Using the Chloroplast Gene ndhF". Systematic Botany. 31 (1): 160–70. doi:10.1600/036364406775971714. S2CID85676723.
References
Whitlock, B. A., C. Bayer, and D. A. Baum. 2001. Phylogenetic Relationships and Floral Evolution of the Byttnerioideae ("Sterculiaceae" or Malvaceae s.l.) Based on Sequences of the Chloroplast Gene, ndhF. Systematic Botany 26: 420–437 (abstract online here).
Wilkie, P., Clark, A., Pennington, R. T., Cheek, M., Bayer, C. & Wilcock, C. C. (2006).Phylogenetic Relationships within the Subfamily Sterculioideae (Malvaceae/Sterculiaceae-Sterculieae) Using the Chloroplast Gene ndhF. Systematic Botany 31(1):160-170.