Maximum likelihood tree based on conserved flagellar proteins depicting the position of R. centenum flagellar systems among other flagellated bacteria. The tree is based on a concatenated alignment of 11 flagellar proteins (Flg) that are present in all primary and secondary flagellar systems . A blue "1" or "2" after the species name indicates primary and secondary flagella systems, respectively. Alpha I (alphaproteobacteria group I) and Alpha II (alphaproteobacteria group II) are boxed. The primary (polar) and secondary (lateral) flagella of R. centenum are in red.