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 white snakeroot leaves and flowers

    White Snakeroot

    Ageratina altissima (formerly Eupatorium rugosum)
    Poisonous Icon

    Poisonous