I took this photo today in Champlain Park, Ottawa. Yes, it's just a pissabed, but it's kinda pretty all the same. A quite useful plant too, even if it's just considered a weed.
I remember mashing the things up as a boy to make a kind of yellow dye -- or a mess... I can't remember which. Or sometimes I'd just collect the seeds and spread them around to see if they'd grown in new places. Much to the chagrin of neighbours I'm sure. Now I just enjoy the leaves in salads.