ΔE 23.1, loose: different enough that you should pick on purpose. Poison Ivy is noticeably darker, more muted than Verdigris.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Poison Ivy is noticeably darker, more muted than Verdigris.
The same difference applies the other way round: Verdigris is noticeably lighter, more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Verdigris on the colour wheel See Poison Ivy on the colour wheel
All matches: Verdigris equivalents · Poison Ivy equivalents