Photo: 1, Ragweed, Greater [Ambrosia trifida]
Greater rag weed. A common allergen. A correspondent states you can eat ragweed leaves before the plant flowers, but it is probably better known as a remedy for HAY FEVER! For the remedy, you would want to collect the plant before it flowers (i.e., before allergenic pollen is present) and dry it for tea or make a tincture in vodka. Then it will be handy when fall hay fever season comes around. It is also perfect for people with cat allergies who get those runny itchy eyes when they come in the same room with felines.
Source: Central Park, Jul 2, 2000