Ditto what David said about Lobelia siphilitica...I expect to have volunteers to share this spring. I should have Lobelia cardinalis as well. I had a few huge, healthy L. cardinalis this year and let them self-seed
I planted a number of woodland natives last year, and hope some come back. Many of them disappeared shortly after I planted them, but perhaps some did so because they were ephemerals. Again,