I have asked this recently, but no one seemed to have any ideas; I have
googled and googled with no success... It came from a fete, with no
label.

The flower is a five-pointed star: the flower is lavender from the
front, but it is pure white from the back.

The leaves are narrow, serrated, and they go up the stem, with one
flower at the end of the stem.

It has a lovely scent.

Flowered profusely in a small tub all summer and still has a few blooms
on it.

Any ideas, anyone? I would love to know, at least, whether it's annual
or perennial....


--
Klara, Gatwick basin