Question: How many plants are poisonous ?

Sarah Harvey answered on 18 Mar 2014:

There are quite a few actually – hundreds that we know about but probably more that people haven’t tried eating! There are also some plants which are poisonous to certain animals for example horses can get poisoned by eating horseradish!

Some plants have poisonous parts but you’d need to eat them in a huge quantity to have any ill effects, one example is apples which have a chemical similar to cyanide in their seeds (you’d have to eat an enormous amount of these though!)