"Greens are a free action" indeed.

We have such a short season, lamb's quarters has a run of maybe three to four weeks? But that's a huge run generally, and so we go stinging nettles -> lamb's quarters -> oh look it's time for domestic veggies

I also especially love its flavour. Though it has a bitter look-alike-when-young plant I'm trying to eradicate.

I think the only true green I'd be unhappy without, from the suite of domesticated greens, is romaine lettuce. Well, and sorrel. There's a lot to be said for a good dandelion-heart salad instead of chicories, for instance.

Hm, ok, I'd miss gai lan too. And napa cabbage, but that's more a storage crop.