Phylogeny In classifications before the use of
molecular phylogenetic methods, Cereeae was one of nine tribes into which the subfamily
Cactoideae was divided. Molecular studies found that these traditional tribes were not
monophyletic. A broader
circumscription of Cereeae, including Browningieae and Trichocereeae and comprising most columnar cacti of South American origin, was found to be monophyletic. With this circumscription, Cereeae was divided into three subtribes:
Rebutiinae,
Trichocereinae and
Cereinae, although Rebutiinae appeared not to be monophyletic. A 2021 study confirmed that Trichocereinae and Cereinae are monophyletic, but that Rebutiinae as then circumscribed was not. A 2023 study proposed six subtribes, which it found to be monophyletic. Rebutiinae was split into four subtribes: Aylosterinae, Gymnocalyciinae, Rebutiinae, and Uebelmanniinae. (Two genera,
Espostoopsis and
Stetsonia, were moved to different subtribes.) The study used a number of large datasets. Two genome-scale datasets agreed that the relationship among Rebutiinae, Trichocereinae, Gymnocalyciinae and Cereinae was as shown below. Limited coverage of the other two subtribes in the two datasets and low resolution in the analysis of a separate gene-based dataset meant that the study could not be certain as to which of Uebelmanniinae and Aylosterinae was the earliest diverging group, although the gene-based dataset suggested it was Uebelmanniinae. }}
Subtribes Historically, the
circumscription of subtribes and genera in the Cereeae has been "highly controversial", and subject to considerable change. Six subtribes were proposed in a 2023 study. The table below compares the 2023 classification with a widely used 2010 classification. ,
Plants of the World Online accepted some genera that were treated as synonyms in the 2010 and 2023 studies. These genera are included in the table together with a note of the name used in one or both of the studies. ==References==