Common Ragweed, Ambrosia artemisiifolia, Sunflower Family (Asteraceae)
Description: Coarse, hairy- stemmed annual with inconspicuous flowers in elongated clusters. Flowers: male, small yellow-green, packed with yellow stamens, borne in heads of 15-20 florets each, arranged on slender clusters 1-6″ (2.5-15 cm) long, near top of plant (hundreds of heads per plant); female, small clusters in small clusters at leaf axils. Leaves: highly dissected, light green, up to 4″ (10 cm) long. Fruit: small, top-shaped, capped with 6 short spines. Height: 1-5′ (30-150 cm)
Habitat: Cultivated fields, waste places, and roadsides.
Comments: This plant, not Goldenrod, is a cause of hay fever, recognized by all who suffer the dicomforting allergy. Pollination is by wind, as indicated by the drabness of the flowers, which do not attract insects. The best control is to permit perennial plants to crowd this annual out. Since the seeds persist into winter and are numerous and rich inoilo. they are relished by songbirds and upland game birds.
flower resources taken from: Niering, William A., Olmstead, Nancy C., National Audobon Society Field Guide to North American Wildlowers. 1979, Chanticleer Press, INC.