The VetFolio article lists one retrospective study published in 2003 specifically naming daylilies. I can find no other evidence of that. In fact, there is a more recent study that gives the botanical background to the daylily and it appears that for years it has biologically been lumped into a broader genus but this study clears that up.
From PubMed from the National Library of Medicine:
https://www.ncbi.nlm.nih.gov/p...
Gayle
