Yes, ditch lilies are part of the daylily family and are the same too. But they are are triploids. So if you wanted to crossbreed other daylilies, they would have to be ditch lilies or triploid daylilies. Which I don't think their are any other triploid daylilies except ditch lilies. Of what I heard from others, ditch lilies are found as a wild flower. But where I live at they aren't really found as one. They are USUALLY found in people's yards and/or in in flower beds.
This is also another kind of ditch lily. I used to have a ton of
these. But now I have the double petal ones, like you have.