Polk salad and Pokeweed are different weeds, er, plants. :') Not sure what Polk salad looks like, not too sure it grows up here. Pokeweed though is semi-edible (small young shoots only), and is (IMHO) gorgeous. Herbaceous, not woody, so it croaks off with the frost, then regrows the next year. S'cool.
Tossing a bit of trivia into the salad, the gunnysacks often used to collect wild greens were often referred to as 'pokes'.
In the days before our sophisticated (refrigerated) food distribution system, a lot of wild greems were popular because they emerged very early in the spring--before anything in the garden was producing and folks were plain hungry for something 'green'. The other plus is that it's 'found food'--the labor being only in the finding as opposed to the planting & tending...and collection is something that kids could be tasked to do.
My mom grew up in the Ozarks--they kept hogs, chickens and a garden. But they also foraged for food--from early greens to summer berries to nuts in the fall. And they ate a lot of small game, too.