Most usually, lunaria is a biennial - flowering the second year and dying. It will set seed and continue the cycle but you will need to sow this annually for the first 2 years until a continuous supply is established. However, there is a perennial one - lunaria rediviva and a hybrid, 'Corfu Blue' which is sold as perennial (mine is in its second year - first year of blooming - so we will see if it returns next year)

I agree with Ralph, sounds like stevia. Mine has overwintered in ground for several years now. I use to keep it in a pot under the house in winter and then started leaving it out (with baby backups under the house) and it came back fine. Like most herbs the leaves are best just before bloom. To use it you just brew it like you would a cup of tea; strain and store the tea water in the fridge for use. Mine is blooming now too. 'If' you confirm it is stevia you can chew a leaf to taste its sweetness. What I use to do was just scrunch and sprinkle the flowers heads (once they've gone to seed) back into a pot of soil and then stored it under my house for the winter. Scads of baby seedlings! I grow my big plant in my herb bed (southern exposure) and let it lay over the winter and clean the dead stems up in the spring when I see new growth starting. To dry, before it blooms I just cut off the stalks about 6 or 8 inches from the ground,... bundle and hang somewhere to dry. Then strip the leaves and store them cool, dark and dry. I normally cut them back about early August and they still have time to put out new growth and go to seed before winter. Since you were going to yank it anyway, I don't think it would hurt it to start picking the smaller tender leaves now, then save your seeds and let it winter over and see what happens.

Smart idea!

Thank you but it was not me, although I would love some seeds if you have any left. I have Boc Choy, Aquilegias, Helleborus and HollyHocks to exchange. doughob@gmail.com