Are both Nigella and Leucanthemella both plants?
Leucanthemella Leucanthemella is a genus of flowering plants in chamomile tribe within the sunflower family.
Helenin Helenin is a phytochemical mixture found in many plant species, including the "Inula helenium" (elecampane) of the Asteraceae family. It is a mixture of two isomeric sesquiterpene lactones, alantolactone and isoalantolactone.