Ключевые слова: allergen, allergic, allergy, alternative, america, biology, canada, canadian, cluster, dense, elegance, erect, essential, fever, flowering, gold, golden, head, herb, herbaceous, illinois, isolated, july, large, late, meadow, medicine, ornamental, perennial, petal, pollen, prairie, preservation, reproduction, rod, staman, stem, strong, summertime, sunlight, tall, up, usa, vast, vibrant, vivid, weed, wilderness, wildflower, wood,