Photo of a bull thistle flowerhead.

    Bull Thistle

    Cirsium vulgare
    fork and knife icon

    Edible

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

    Teasels

    Dipsacus fullonum and D. laciniatus
    invasive icon

    Invasive

    Photo of white heath aster flowers

    White Heath Aster

    Symphyotrichum pilosum (formerly Aster pilosus)
    Photo of yarrow or common milfoil flower cluster

    Yarrow (Common Milfoil)

    Achillea millefolium