This year, for some reason, we have a bumper crop of curly dock (Rumex crispus) on-site. Curly dock is another of those pernicious invasive species (it's listed as a noxious weed in 46 states by the U.S. Department of Agriculture), much like its Polygonaceous relative, Japanese knotweed. Like knotweed, it's delicious.
While the young leaves can be eaten raw, the older leaves are best parboiled before consumption in order to reduce the oxalate levels. This sucker has a date with my stewpot:
Later in the year, the curly dock plants will produce edible seeds which can be ground into a flour, much like the seeds of dock's relative, buckwheat.
Like redbud, this is a plant that keeps on giving... and by taking, I'm helping to reduce its spread.
Edit: I would be remiss if I didn't mention that the juice of the curly dock is commonly considered the "antidote" to the sting of the nettle. I haven't put this to use because I have a pretty high pain threshold (I'm a fighter, so it's a necessity), and the burn of the nettle isn't all that bad.