Belladonna, Pennyroyal, foxglove,cowbane,holly, ivy, just to name a few that can be lethal if ingested...
Those are the plants that keep a flower garden safe from browsing deer. They know not to eat them...Keeps rabbits out also...But I live in the country and don't need to worry about kids...The pods from the sweet pea can also be poison...When raising my 5 kids I knew by heart the phone # of Poison Control...Also learned how to get my kids to throw up before taking them to the doctor...Those lovely red berries on yews are big time no no's.
Foxglove is one of my favorite flowers, beautiful...