Are daylilies ~actually~ poisonous to cats?

For reference: https://garden.org/thread/view/15995/Cats-and-Daylilies---survey-results/

This has been bugging me for a little while. A lot of the people I know IRL who are growies with cats are sure that daylilies are very poisonous to cats. One of mine likes to nibble at my daylilies and has never had a problem, and it seems very plausible to me that people have mixed up daylilies with other kinds of lilies. Does anyone have any further experiences or info about this? Obviously I'm not going to force-feed daylilies to my cat or let him gnaw on them endlessly, but I also hate to let a good plant have a bad reputation.

I've never understood why one would worry about plants and cats, or dogs for that matter. Typically, these animals won't eat things that are going to kill them, unless some unknowing human grinds it up and feeds it to them. I have always gardened with poisonous plants and my pets have never killed themselves, foxglove, nicotiana, monkshood. They know better, if they don't, they should.

Meg, below are the list of symptoms of Lily Nephrotoxicity to watch for in your cat. All lilies are poisonous to cats

Drooling
Vomiting (pieces of plant in the vomitus)
Loss of appetite
Increased urination, followed by lack of urination after 1 to 2 days
Dehydration

I would tend to discount personal observations on something like the poisonous properties of lilies on felines when there is plenty of documented evidence that shows they are. I cannot account on why your cat does not get sick though I suspect it is because the amounts ingested are too low to have any immediately discernible effect. The long term effects of Lily Nephrotoxicity is kidney failure, so it is possible small amounts over time could cause long term effects that are not easily observed.

The cat may be self-medicating.  Probably half of ornamental plants are poisonous, but they are also used medicinally in various ways.  Even belladonna, stinging nettle, etc.  I have day lilies and stray cats I take care and both are doing fine.