Lambsquarters are generally considered a weed. You have probably yanked them out of your own flowerbed and never knew that they were good to eat. They taste like swiss chard. Be sure not to over cook them. I was surprised that no one else had posted about them here. Be sure that you check that you are picking the real thing, here is a good reference http://www.ppws.vt.edu/scott/weed_id/cheal.htm there are many more, but this one has a good picture.