Incredibly poisonous, the assassins poison of choice. Bulgarian assassins in London got a defector there with a device mounted in an umbrella that injected a couple of ball-point-pen balls coated with ricin.
The bean is shiny, attractive, the shape of a jellybean, and just a bit smaller. They scatter from the seed case and sit on the ground. One is enough to kill a child, two or three can handle an adult. Even if you live through it your health can be ruined for life.
I won't grow them, and I'll kill any I can.