blue porterweed, Stachytarpheta jamaicensis

Blue porterweed is a common plant in open areas in the American tropics. A closely related species grows in the Old World. They are used interchangeably for food and medicine. Porterweed is sometimes cultivated. Tender parts of the plant are eaten. The plant is used to make a refreshing tea. In herbal medicine it is a depurative. How did I get this far without knowing what that is? All this despite the plant's mild toxicity. With us it grows in AL, FL, and HI. Collier Co FL, 1/25/13.