First of all, I've had cats and gardens with lilies in them for years
and have NEVER had a problem.

Well, that's a comforting thought.

Secondly, daylilies aren't true lilies, and that seems to be what
this article is talking about.

To quote the article, "These popular springtime plants--including
Easter lily, tiger lily, rubrum lily, Japanese show lily and some day
lilies--can cause kidney failure in cats if ingested." So they are
including "some" day lilies in the poisonous group.

Day lilies aren't Lilium. I don't know whether they're poisonous or not, but
I've never seen cats eating them. Is your cat inclined to eat random plants?

Actually, I did see my cat chewing on the grass-like stalks last week.
No obvious ill effects to date, but I am concerned.

-F