Jewelweed is a vigorous native self-seeder that grows up to 4' high in a moist location. Can be a nuisance but then again it isn't poisonous, doesn't have prickles and doesn't make burrs. Plus the bumblebees like it. Some people say that the juice of jewelweed will ease the itch of poison ivy. Never worked for me, but I'm just a sample of one.
The jewelweed flowers are quite interesting when you see them up close.
Ligularia also likes a damp location. It's a rough looking plant but I'll take any blooms I can get at this time of year.
Not sure what this native is but it stays in a clump and blooms well at this time of year. The white fluffy flowers brightens up a shady spot nicely.