“Cladogram (family tree) of a biological group, showing the last common ancestor of the composite tree, which is the vertical line ‘trunk’ (stem) at the bottom, with all descendant branches shown above. The blue and red subgroups (at left and right) are clades, or monophyletic (complete) groups; each shows its common ancestor ‘stem’ at the bottom of the subgroup ‘branch’. The green subgroup is not a clade; it is a paraphyletic group, which is incomplete here because it excludes the blue branch even though it is also descended from the common ancestor stem at the bottom of the green branch. The green subgroup together with the blue one forms a clade again.” (emphasis mine)