After the publication of this work  we became aware of the fact that in Supplementary File 2 some of the sequence identifiers (i.e. CLE numbers) of the Medicago truncatula CLE protein sequences in the multiple alignments were incorrect. Table 1 shows the corrected CLE numbers. Additional file 1 and Additional file 2 show a full corrected list of all CLE peptides with their corresponding groupings. The tables within these files also include identifiers for those sequences that were not grouped in Figure 2 of the original article .
We regret any inconvenience that this inaccuracy in the data might have caused.