What is Devil's Umbrella?
1.
Poison hemlock or water hemlock, Conium and Cicuta respectively. They are both deadly poisonous umbelliferous plants. The poisons in these plants act differently: Poison hemlock (the hemlock of Socrates' time) contains coniine, which causes ascending paralysis and suffocation, and water hemlock contains cicutoxin, which causes violent convulsions and nervous system collapse.
That's a devil's umbrella, Johnny. Don't even THINK of picking it!
See