Photo of a musk thistle blooming flower head.

    Musk Thistle (Nodding Thistle)

    Carduus nutans
    invasive icon

    Invasive

    Photo of sensitive brier flowers

    Sensitive Briar

    Mimosa quadrivalvis (also Schrankia nuttallii)
    Photo of cut-leaved teasel showing flowerhead and joined, cuplike leaves.

    Teasels

    Dipsacus fullonum and D. laciniatus
    invasive icon

    Invasive