There are quite a few plants which can kill you but it's probably better that they're not widely known. I knew a guy who worked as an ER doc and he talked about

There are quite a few plants which can kill you but it's probably better that they're not widely known. I knew a guy who worked as an ER doc and he talked about how in Sri Lanka there was a widely known and common plant which could kill you, and people overdosed on it regularly (suicide attempts).