Plant for ID
I'd really appreciate it if someone could ID this plant for me. It sprang up in a tub this spring completely unexpected. The compost in the tub is not new and we haven't had it in our garden and our neighbour hasn't, so assume a friendly bird has 'dropped' a seed in!
It's not an unpleasant plant, and the bees seem to really like it so unless it's particularly bad or invasive we'll probably keep it!