Photo of a giant ragweed plant.

    Giant Ragweed

    Ambrosia trifida
    Photo of pale Indian plantain flower clusters.

    Pale Indian Plantain

    Arnoglossum atriplicifolium (also Cacalia atriplicifolia)
    Photo of white snakeroot leaves and flowers

    White Snakeroot

    Ageratina altissima (formerly Eupatorium rugosum)
    Poisonous Icon

    Poisonous