Diverged from their closest living relative ca. 383 million years ago, Selaginellaceae are among the oldest lineages of vascular plants. Currently, ca. 750 species are placed in a single genus, ignoring the ancient diversity of its deeply diverged clades and devaluing it as a triage level for judging biodiversity value. Based on a new phylogeny and analysis, Zhou & Zhang reclassified Selaginellaceae into 7 subfamilies and 19 genera. This will foster more efficient communication, promote additional research, and help conservation.