http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm393028.htm
http://catsingardens.blogspot.com/2015/10/gardenig-is-more-fun-with-cats.html
Here is a List of SAFE Plants for Cats:
http://catsingardens.blogspot.com/2015/11/nontoxic-plants-for-cats.html
In the last several years, many veterinary webpages and cat-related websites have sprung up to educate cat owners on the dangers of lilies, such as noliliesforkitties.com. Here is a graphic shared on one of them:
Top Photo Source: FDA
(This is an update of an earlier Cats in Gardens blog post.)