Both the roots and the flower/buds have been used in Asia - the roots medicinally and the buds/flowers for food items. Daylilies are grown as an agricultural/commercial crop for their buds/flowers in Asia.
I have not seen any research reports that indicate that eating the buds/flowers has caused problems. None of the research that looks at the toxin in the roots has mentioned toxin present in other parts of the daylily.
Before I knew about the toxin I ate the flower buds twice. After I learned that there was a toxin in the roots I decided that the buds/flowers were not a food that I had any desire to eat simply to be on the safe side.
The same toxin is present in plant species closely related to daylilies. In those species the toxin has been found in the leaves. Also in those species it is sometimes present and sometimes absent.
