The COM clade is non-monophyletic; constituent families should be placed in malvids
The COM clade, as circumscribed by two studies (Matthews &Endress, 2006; Zhu et al., 2007 ), contains approximately 19,000 species, or approximately one-fifth of all superrosids (APG IV, 2016 ). Despite rapid progress in elucidating the major branches of superrosid phylogeny, the position of the COM clade has been a subject of much debate. We found that the COM clade was non-monophyletic, and the three constituent families appeared with malvids based on coalescent and concatenation-based methods (Fig. 5, 6 ). The sister relationship between Celastrales and Malpighiales was strongly supported, and Oxalidales was sister to a clade comprising Sapindales, Malvales, and Brassicales with strong support in concatenation phylogeny, which was also reported by Zhao et al. (2016) . In our coalescent tree, Celastrales and Malpighiales were also sisters with strong support, and Oxalidales and Sapindales formed a clade with LPP = 0.89. Thus, the CM clade and Oxalidales should be members of malvids rather than fabids, which is also supported by floral features shared between the COM orders and malvids (e.g., the inner integument of the ovule, contorted petals, Matthews & Endress, 2006 ).