Annual ragweed
Ambrosia artemisiifolia
family
Asteraceae
origin
Exotic
declaration
Category 3 Restricted Matter (Biosecurity Act 2014)
Must not be distributed or disposed. This means it must not be released into the environment unless the distribution or disposal is authorised in a regulation or under a permit.
Common names
Annual ragweed, Ambrosia, American wormwood, Carrot weed, Hay-fever weed, Hog weed, Common ragweed.
An upright herbaceous plant (growing up to 2 m tall) that forms a basal rosette of leaves during the early stages of growth. Its rounded stems bear deeply divided leaves that are fern-like in appearanceseparate male and female flower-heads are formed on the same plant. The drooping male flower-heads are borne in elongated spike-like clusters (up to 20 cm long) at the tips of the branches. The inconspicuous female flower-heads are borne in the upper leaf forks.
Impact
Impact
Annual ragweed (Ambrosia artemisiifolia) is mainly seen as a weed of disturbed sites and pastures in eastern Australia. However, it is also regarded as an environmental weed in some parts of New South Wales and Queensland and is listed as a priority environmental weed in at least one Natural Resource Management region. This species can become very abundant in overgrazed natural pastures, as well as in riparian areas (i.e. along creek banks, on floodplains, and on sandy creek beds), where it replaces native species.In New South Wales, annual ragweed (Ambrosia artemisiifolia) is mainly a problem in coastal districts north of Sydney and it appears on several environmental weed lists in this region (i.e. it is an alert weed in the Sydney North region, is on the NSW North Coast environmental weed survey list, and is listed as an environmental weed in Byron Shire). It has also been recorded in conservation areas in north-eastern New South Wales (i.e. Billinudgel Nature Reserve) and south-eastern Queensland (i.e. Tugun Hill Conservation Area). Dense stands of this and other weed species are also seen as a threat to the integrity of remnant littoral rainforests in the coastal regions of New South Wales, and these rainforests are regarded as an endangered ecological community in this state.Annual ragweed (Ambrosia artemisiifolia) is also considered to be an invasive species in Europe (e.g. France and Switzerland) and parts of Asia, although it is not an extremely aggressive species. It also displaces native vegetation in these countries, especially after disturbance events which put competitive pressures on the native flora.A stem-galling moth (i.e. Epiblema strenuana) and a leaf-feeding beetle (i.e. Zygogramma bicolorata), which were introduced as biological control agents of parthenium weed (Parthenium hysterophorus), also attack annual ragweed (Ambrosia artemisiifolia) and may reduce its invasiveness in sub-tropical regions.For more information from the Queensland Government
Location
Location
Characteristics
Characteristics
Similar Species
Similar Species
Annual ragweed (Ambrosia artemisiifolia) is mainly seen as a weed of disturbed sites and pastures in eastern Australia. However, it is also regarded as an environmental weed in some parts of New South Wales and Queensland and is listed as a priority environmental weed in at least one Natural Resource Management region. This species can become very abundant in overgrazed natural pastures, as well as in riparian areas (i.e. along creek banks, on floodplains, and on sandy creek beds), where it replaces native species.In New South Wales, annual ragweed (Ambrosia artemisiifolia) is mainly a problem in coastal districts north of Sydney and it appears on several environmental weed lists in this region (i.e. it is an alert weed in the Sydney North region, is on the NSW North Coast environmental weed survey list, and is listed as an environmental weed in Byron Shire). It has also been recorded in conservation areas in north-eastern New South Wales (i.e. Billinudgel Nature Reserve) and south-eastern Queensland (i.e. Tugun Hill Conservation Area). Dense stands of this and other weed species are also seen as a threat to the integrity of remnant littoral rainforests in the coastal regions of New South Wales, and these rainforests are regarded as an endangered ecological community in this state.Annual ragweed (Ambrosia artemisiifolia) is also considered to be an invasive species in Europe (e.g. France and Switzerland) and parts of Asia, although it is not an extremely aggressive species. It also displaces native vegetation in these countries, especially after disturbance events which put competitive pressures on the native flora.A stem-galling moth (i.e. Epiblema strenuana) and a leaf-feeding beetle (i.e. Zygogramma bicolorata), which were introduced as biological control agents of parthenium weed (Parthenium hysterophorus), also attack annual ragweed (Ambrosia artemisiifolia) and may reduce its invasiveness in sub-tropical regions.For more information from the Queensland Government
