Plant ID

[Spindelina]

I think this is probably a weed but it's about to flower so it's time to decide! Any ID for it?

The leaves don’t look right but is it annual mercury, Mercuralis annua? I can’t think what else it could be. But as it’s so near to flowering, why not wait? The seeds won’t start to form until the flowers are dying, and the seeds won’t scatter until the seed pod is ripe.

It’s green and attractive enough, just leave it!