Hi Everyone,
I’m also not being especially successful at finding any more resources about poisionious plants in NL .. great to read the above already found!
I have however stumbled across this fantastic database of a lot of interesting plannts across all of the botanic gardens in NL, also nicely categoried and including a category called ‘PRECAUTIION’, which I think contains the poisionous plants to be found in the botanic gardens across NL: