The retrospective study was based on lay identification of the plants that were believed to be involved. If I recall correctly that's also the one that lists species of daylilies but they were not actually studied. This has resulted in some citing papers implying those daylilies were implicated in the poisonings but they were just given as examples of daylily species names (if I recall correctly two were synonyms and one is an outdated name that belonged to a hosta). There is no way that home gardeners or veterinarians could identify daylilies to species.
