Photo of American feverfew flower cluster.

    American Feverfew

    Parthenium integrifolium
    Photo of a musk thistle blooming flower head.

    Musk Thistle (Nodding Thistle)

    Carduus nutans
    invasive icon

    Invasive

    Photo of leaf cup flower

    Pale-Flowered Leaf Cup

    Polymnia canadensis
    Photo of cut-leaved teasel showing flowerhead and joined, cuplike leaves.

    Teasels

    Dipsacus fullonum and D. laciniatus
    invasive icon

    Invasive

    Photo of yarrow or common milfoil flower cluster

    Yarrow (Common Milfoil)

    Achillea millefolium