Ambrosia peruviana Cabrera 1941 not Willd. 1805 nor DC. 1836
Iva monophylla Walter
Ambrosia artemisiifolia, with the common names common ragweed, annual ragweed, and low ragweed, is a species of the genus Ambrosia native to regions of the Americas.[2][3]
Taxonomy
The species name, artemisiifolia, is given because the leaves were thought to bear a resemblance to the leaves of Artemisia, the true wormwoods.
It has also been called the common names: American wormwood, bitterweed, blackweed, carrot weed, hay fever weed, Roman wormwood, short ragweed, stammerwort, stickweed, tassel weed.[2][4]
It is the most widespread species of the genus in North America, to which most of the other species of Ambrosia are endemic. During the summer it causes allergic reaction in those that are susceptible.
It is much-branched, and grows up to 70 centimetres (2.3 ft) in height.[9] The pinnately divided soft and hairy leaves are 3–12 centimetres (1.2–4.7 in) long.[9]
Its bloom period is July to October in North America.[9] Its pollen is wind-dispersed, and can be a strong allergen to people with hay fever.[4][10]
It produces 2–4 mm obconic green to brown fruit.[9] 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.[4]
Galls
This species is host to the following insect induced galls:
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 Macaronesia; Oceania in Australia, New Zealand, and Hawaii; and Southwestern North America in California and the Southwestern United States.[2][9][11][12][13][14][15][16] A scientific study investigated the genomic basis of invasiveness in Ambrosia artemisiifolia, introduced to Europe in the late 19th century, by resequencing 655 ragweed genomes, including 308 herbarium specimens collected up to 190 years ago.[17] In invasive European populations, the study found selection signatures in defense genes and lower prevalence of disease-inducing plant pathogens. Together with temporal changes in population structure associated with introgression from closely related Ambrosia species, escape from specific microbial enemies likely favored the remarkable success of common ragweed as an invasive species.
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.
Ragweed control
As of 2005[update] several herbicides were effective against common ragweed, although resistant populations were known to exist.[18] In 2007 several Ambrosia artemisiifolia populations were glyphosate resistant, exclusively in the USA.[19]
As of 2014[update] the ragweed leaf beetle, Ophraella communa, has been found south of the Alps in southern Switzerland and northern Italy. Many of the attacked plants were completely defoliated.[20]Zygogramma suturalis was introduced to Russia, and then China, for ragweed control, with very positive initial results.
SMARTER is a European interdisciplinary network of experts involved in the control of ragweed, health care professionals, aerobiologists, ecologists, economists, and atmospheric and agricultural modellers.[21]
Ambrosia artemisiifolia is used in phytoremediation projects remediating soil pollution, for removing heavy metals such as lead from contaminated soil.[24]
^Hokche, O., P. E. Berry & O. Huber. (eds.) 2008. Nuevo Catálogo de la Flora Vascular de Venezuela 1–859. Fundación Instituto Botánico de Venezuela, Caracas.
^Jørgensen, P. M., M. H. Nee & S. G. Beck. (eds.) 2015 en adelante. Catalogo de las plantas vasculares de Bolivia (adiciones).
^Cf. www.ragweed.euArchived 2013-06-11 at the Wayback Machine. The project ran from 2013 to 2017 as part of the EU programme COST. More than 120 participants from 33 countries were active during 2013.
^Wang, P. H.; Xu, J.; Wu, M. Y. (1993). "Chemical constituents of ragweed (Ambrosia artemisiifolia L.)". Zhongguo Zhong Yao Za Zhi. 18 (3): 164–166, 191. PMID8352903.
^Huang, Jianwei W.; Chen, Jianjun; Berti, William R.; Cunningham, Scott D. (1997). "Phytoremediation of Lead-Contaminated Soils: Role of Synthetic Chelates in Lead Phytoextraction". Environmental Science & Technology. 31 (3): 800–805. Bibcode:1997EnST...31..800H. doi:10.1021/es9604828.