I have grown seeds labeled Matricaria parthenium, feverfew. The cultivar is 'Ultra Double White'. But in the database feverfew is listed as Tanacetum perthenium. Yet I did not see in that listing that Matricaria parthenium is an accepted botanical synonym. So I am unsure how to add my plant to the database. Oh database sages please advise...

I've added this for you Jennifer.
Feverfew (Tanacetum parthenium 'Ultra Double White')

We need to add Matricaria parthenium as a synonym to all of our Tanacetum parthenium entries.

Much appreciated!