Explore a dated tree of the British flora

For our 2023 PNAS paper, Genetic factors predict hybrid formation in the British flora, we needed a phylogeny of (almost) every native British plant species. The result is a dated tree of 1,406 species, which has turned out to be useful well beyond that paper for seeing how British plants are related, and how long ago their lineages split.

You can now explore it below. Hover over (or tap) any branch to see the clade it belongs to and how old it is, click to zoom in, or search for a species, genus, family or order. Zoom in far enough and every species is labelled.

Loading 1,406 species…

1,406 species

Seed plants of the British flora, rooted about 360 million years ago. Hover over a branch to explore, or click to zoom.

Maximum likelihood tree from rbcL, matK and ITS, inferred with IQ-TREE and dated with treePL using fossil calibrations from Ramírez-Barahona et al. (2020). Branch colours mark major clades and the outer rings mark orders and, when zoomed in, families. Drawn with lwPhylo; the original notebook is on Observable, and the Newick file is free to download.

A few things stand out. Almost all of the British flora descends from the flowering plant radiation of the Cretaceous, yet the big families (grasses, sedges, daisies, crucifers) only began to diversify within the last 50 million years. Some of the largest genera are strikingly young: the 73 Carex species in the tree share an ancestor only about 10 million years ago, and our 18 Euphrasia about 4 million.

If you use the tree, please cite:

Brown MR, Hollingsworth PM, Forrest L, Hart M, Leitch IJ, Jones L, Ford C, de Vere N, Twyford AD (2023). Genetic factors predict hybrid formation in the British flora. Proceedings of the National Academy of Sciences, 120(16), e2220261120.