There are many plants for the house and garden that are poisonous for cats. Most cats won't even touch these plants, but we can't rule out the possibility that they can come in contact with the poisonous juices by playing with twigs, shoots, large seeds or pods. So stay alert!
It's really the best to forbid your cat to eat from any plant or play with it, with exception of course of it's own clump of grass. We need to be especially careful with the behavior of our kittens, for they are in the habit to play or nibble with/on anything that looks like a plant. Luckily poisoning by plant is rare.