Four canonical long PIN clades are found in the angiosperms.

(A) Bayesian phylogram of angiosperm long PIN sequences. Basal plant groups (Physcomitrella patens and Selaginella moellendorffii) are not visible, see Figure S1 in supplementary material for complete phylogeny. All nodes without asterisks (*) have at least 0.95 posterior probability. Arabidopsis sequences are marked with stars. Brachypodium SoPIN1, PIN1a, and PIN1b are marked with arrows. Major clades are labeled at right. Plant families at major phylogenetic nodes are colored according to (B). Each sequence name is followed by a family abbreviation also defined in (B). (B) Summary tree showing the relationships amongst the angiosperm families sampled in (A), monocot and eudicot groups are labeled [57]. (C) Summary of inferred phylogenetic relationships between Arabidopsis PIN1 and Brachypodium SoPIN1, PIN1a, and PIN1b. The “X” indicates the loss of Arabidopsis SoPIN1. Scale: 0.08 substitutions per site.