Poisonous plants

I thought it might be a good idea to have a list:

Ragwort
Hemlock
Purple Milk Vetch
Yellow Star Thistle
St. Johns Wort
Privet
Buckthorn
Laburnum
Rhododendron
Laurel
Yew
Acorns from oak trees

Is Purple Toadflax poisonous to horses? Seem to remember reading somewhere that someone had some in their field after it had been flooded and they were advised to get rid

And Foxglove.

And apparently sycamores have something to do with atypical myopathy (or something like...)

Can't find anything on Google about it and horses.

Did find a couple of things that say they throw out a lot of seeds. I'd therefore be tempted to dig it up.