Appearance
''Ambrosia artemisiifolia'' is an annual plant that emerges in late spring. It propagates mainly by rhizomes, but also by seed.It is much-branched, and grows up to 70 centimetres in height. The pinnately divided soft and hairy leaves are 3–12 centimetres long.
Its bloom period is July to October in North America. Its pollen is wind-dispersed, and can be a strong allergen to people with hay fever.
It produces 2–4 mm obconic green to brown fruit. It sets seed in later summer or autumn. Since the seeds persist into winter and are numerous and rich in oil, they are relished by songbirds and upland game birds.
Naming
Common ragweed, ''Ambrosia artemisiifolia'', is a widespread invasive species, and can become a noxious weed, that has naturalized in: Europe; temperate Asia and the Indian subcontinent; temperate northern and southern Africa and Macronesia; Oceania in Australia, New Zealand, and Hawaii; and Southwestern North America in California and the Southwestern United States....hieroglyph snipped...Common ragweed is a very competitive weed and can produce yield losses in soybeans as high as 30 percent. Control with night tillage reduces emergence by around 45 percent. Small grains in rotation will also suppress common ragweed if they are overseeded with clover. Otherwise, the ragweed will grow and mature and produce seeds in the small grain stubble.
Its wind-blown pollen is highly allergenic.
Distribution
The plant is native to: North America across Canada, the eastern and central United States, the Great Plains, and in Alaska; the Caribbean on Cuba, Hispaniola, and Jamaica; and South America in the southern bioregion , the western bioregion , and Brazil. The distribution of common ragweed in Europe is expected to expand northwards in the futureIt is the most widespread species of the genus in North America, which most of the other species of ''Ambrosia'' are endemic to.
Ambrosia is also widely distributed in Ukraine, specifically in Central and South regions. During summer period it often causes the allergy reaction from some people. The highest risk time is in August
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