An acquaintance recently had to leave her poor cat at the vet overnight on a drip following a run in with a lily that she had taken care to put in a room she didn't let her cat into. Well of course the cat had other ideas, snuck in unobserved and ate some of the lily. Happily the danger was discovered in time, the cat recovered following treatment and the cat's mum is never going to risk lilies anywhere in the house again.
I just thought it would be worth posting this as there are several people around with new kittens and cats. The really scary thing about lilies is that the cat doesn't even have to help itself to the plant - the highly toxic pollen can just fall on its coat and it will then ingest it later when it grooms. Lily poisoning can lead to kidney failure and death if not treated immediately.
There's a list here of indoor and outdoor plants that are toxic to cats, some advice on the subject of prevention and some info on poisoning symptoms that would necessitate a trip to the vet.
www.icatcare.org/advice/keeping-your-cat-safe/cats-and-poisonous-plants
Also
www.noliliesforcats.com/site/view/169876_FAQ.pml