Photo of a giant ragweed plant.

    Giant Ragweed

    Ambrosia trifida
    Photo of mist flower or wild ageratum plants with flowers

    Mist Flower (Wild Ageratum; Blue Boneset)

    Conoclinium coelestinum (formerly Eupatorium coelestinum)
    Photo of many blooming ashy sunflower plants, showing gray-green leaves.

    Sunflowers

    Helianthus spp.
    Photo of a tall thoroughwort plant in bloom.
    Photo of cut-leaved teasel showing flowerhead and joined, cuplike leaves.

    Teasels

    Dipsacus fullonum and D. laciniatus
    invasive icon

    Invasive

    Photo of white snakeroot leaves and flowers

    White Snakeroot

    Ageratina altissima (formerly Eupatorium rugosum)
    Poisonous Icon

    Poisonous