Can you post a photo? It really would help us to help you.

Sounds like Florida Betony. A native wild flower in Florida but has become a problem weed in many parts of the US. Also known as Rattle Snake Weed due to the tubers look like the rattler of the Rattle Snake. I used to call it a mint because of the smell. It is an edible plant (always have a positive ID before eating any plants). I haven't tried it myself but have heard people like to slice up the tubers for salad. I will attempt to load an image of it.

{{gwi:1344940}}

That's it! Thank you for posting. How in the world did these things get into the raised bed? I bet there were 75 of these things. I sure hope they do not come back.

It'll be back, I'd bet money on it.