You don't say where you are located but here in Michigan Purple Loosestrife is a very bad invasive. I know it is pretty. But check your local extension office to see if it might be on the list of invasive species in your area.
I think the poster is from Albania like his username suggests, and the plant is likely Lythrum salicaria, it is being used as a traditional medicinal plant among the Albanian people.. https://www.researchgate.net/p...
