Plant identification help please

We spent the afternoon in the garden yesterday. It was a rather dull and cold Bank Holiday unfortunately but we still all had a great time and a lovely BBQ - thanks Jo.

Katherine will update you all on how it went hopefully but I was wondering if any of you would be able to tell us what this plant is please? It has self seeded from last year but unfortunately we cannot remember what was there last year as it all came down from the show.

I took a large Rosemary bush from my back garden and took it to the school garden to go next to the compost bin.

Here's a view of everyone pottering away at their various tasks.