Photo of common cinquefoil plants with flowers

    Common Cinquefoil

    Potentilla simplex
    Photo of a giant ragweed plant.

    Giant Ragweed

    Ambrosia trifida
    Photo of several big bluestem seed heads against a blue sky.

    Grasses

    All true grasses (species in the grass family).
    Photo of whorled milkweed flowers.

    Milkweeds

    Subfamily Asclepiadoideae
    Photo of many blooming ashy sunflower plants, showing gray-green leaves.

    Sunflowers

    Helianthus spp.