Heather, it sounds as if you've seen Poke (also known as Pokeweed and Poke Salat). I've heard the rumors of it being poisonous, and perhaps it is, but I'm skeptical. The link says the whole plant is poisonous, but when I was a kid I was told the berries were poison, but the birds liked them. As with any greens, big old leaves can be tough, but we always tried to pick the young tender leaves, boiled them, drained that water off, then added fresh water and cooked them with whatever seasonings we wanted for any greens; i.e., salt, pepper, maybe a little bacon or oil. At the table I prefer mine with a little pickle juice (sweet or dill either one is good; and plain vinegar ain't bad). In other words, we only changed the water once; not twice. And Mother always canned a lot of it and after pressure cooking in the jars, it was as tender as any spinach. I've never bought any in the grocery store, but I have seen canned Poke in a grocery store.