Figure 4.42 Origin of root-nodule symbiosis with rhizobia in angiosperms. Angiosperm phylogeny of 3,467 species showing reconstruction of node states. Branches are coloured according to the most probable state of their ancestral nodes. A star indicates precursor origin. Turquoise and yellow band indicate the legumes and the so-called nitrogen-fixing clade, which contains all known nodulating angiosperms. Grey and white concentric circles indicate periods of 50 million years from the present. The positions of some important angiosperms are indicated with drawings (illustrations by Floortje Bouwkamp). (Reproduced by permission from Macmillan Publishers Ltd from G.D.R. Werner et al. Nature Comms 5: 5087, 2014)