dangerous giant hogweed intertwined with grapevine

apiaceae biennial blindness blistering bristles burning careful carrot danger dangerous detail field fingerlakes florets flower flowers giant grapevine heracleum herb herbicide hogweed hollow huge intertwined invasive mantegazzianum nefarious noxious nys perennial plant poison rays roadside sap scar scarring stalk stayaway stem tall toxic watchful weed white