Figure 1.

Phylogeny of major groups of land plants. Based on [13,15,19,20]. Approximate numbers of species and available genome sequences are given, and approximate times of major divergences are indicated. Ferns as a whole include lineages that diverged from one another prior to the divergence of the major seed plant clades. The most recent common ancestor of all leptosporangiates arose approximately 280 mya [17,18]. The ancestors of Ceratopteris and Azolla diverged from each other ca. 200 mya, well before the divergence of monocots and eudicots. Dates obtained from TimeTree [21,22].