Is that what I'm looking at? Purchased this property a few years ago. Every year, I get a bunch of this popping up in wet areas. No seeding has been done and it definitely seems to be spreading. I highly doubt anyone in the past ever seeded it.
Individual plants tend to be 4-5ft tall and 2-3ft across. It produces new seed heads all summer long.
Considering harvesting seed heads and spreading in my wetlands.