Bayesian likelihood tree for Selaginella EXPA genes with selected rice, Arabidopsis , and Populus sequences. Burnin was set to 1,000,000. Tree was manually rooted at AtEXPB3. Clade and groupings are marked with circles (or bars when they are poorly resolved as in the case of clades EXPA – I, EXPA – II, EXPA – III and EXPA – VI). Selaginella sequences are labeled in orange and boxed, rice in blue, Arabidopsis in black, and a Populus in brown.