branch of ambrosia plant on white background. ragweed bush. allergy-causing plant. weed bursages

branch ambrosia plant isolated white background ragweed bush allergycausing weed bursages flowering medical problem stammerwort closeup wormwood young botanical sick object illness health allergenic wild bloom herb natural detail fresh blooming allergic asthma allergy nature green summer seasonal pollen autumn flower leaf medicine botany allergen artemisiifolia season annual fever yellow flora