I was pulling weeds in the vegetable garden this weekend, and came across this weed in the basil patch. I was about to pull it when I realized it was full of Japanese beetles, and there were no Japanese beetles on the basil.
This weed was functioning as a Japanese Beetle Attractant Plant, and a neat way to not use Japanese Beetle pesticides and traps. This is one of those simple organic Japanese Beetle controls one can use to deal with the beetles.
I have yet to identify the weed, as the weed identification sites I have visited have yet to yield an answer.
But think twice before pulling up a plant that is full of garden pests, its probably keeping those pests from your vegetable plants.