Phylogenetic network from the Bayesian majority rule consensus tree of the first intron of the nuclear PISTILLATA ( PI ) gene in Lepidium . The network is reconstructed using the Huber et al.  algorithm. Strongly supported branches from the Bayesian consensus tree, with posterior probabilities >0.90 and/or maximum likelihood bootstrap values >75%, are indicated in bold. Allopolyploids result from curved lines. Our four study species are highlighted by colored lines, and the other 17 non-focal allopolyploids are depicted by lighter, thinner blue lines. Ancestral genomes contributing to our study species L. kirkii, L. naufragorum, L. sisymbrioides, and L. tenuicaule are indicated in colors matching Figure 1: yellow, purple, red, and green lines, respectively. Four distinct ancestral genomes (red) contributing to L. sisymbrioides are numbered on the right (1a, 1b, 2 and 3) with their respective biogeographical origin: Am, America; As, Asia; Au, Australia; ANZ, Australia/New Zealand.