I don't know.
This is the first one that's ever survived long enough to get more than 3 inches high...
Are they biennial, maybe? Foliage one year, bloom the next, then reseed? Some of my rudbeckia seem to be like that--the black-eyed susans seem to only show up every second year
"We are--each of us--dying; it's how we live in the meantime that makes the difference."
"It's not what you gather, but what you scatter that tells what kind of life you have lived!"
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."