Love this plant! We got given a few unknown varieties that we introduced and they have started to naturalize. Great to add to a salad, or just green manure/mulch. Really don't mind them coming up in the garden beds in bulk. there can be thousands in a few square meters from one previous plants dropped seed and they can easily just be chopped and dropped when the time is right to plant something else. Many times we'll take a stalk full of seed and go for a walk shaking it around..
Thanks to this article and photos we have clarified some of them as virdis and caudutus! We also have a really beautiful silver one.