This plant appeared in a pot in my yard, I don't know whether I got it in a plant exchange or whether it self-seeded there. I planted it out to see what would become of it and when it flowered it was clear that it was Hofmann's ringed bellflower. It is monocarpic, which means it dies after flowering, so it remains to be seen whether it self-seeded. I did not have the good sense to collect seed from it. It is a very pretty plant bearing white flowers in July - August and grows best in well drained soil in sun or partial shade.