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Blue heliotrope
(Heliotropium amplexicaule)
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The Problem
Heliotropium amplexicaule (blue heliotrope) is native
to South America, occurring in northern and central Argentina,
southern Bolivia, Uruguay and the extreme south of Brazil.
It was introduced into Australia as an ornamental plant in
the late 1800s. Over the last 40 years there has been a rapid
and continuing expansion of its range and there are now widespread
infestations in south-east Queensland and northern New South
Wales, with scattered colonies extending into Victoria and
further into South Australia.
Blue heliotrope infests over 110,000 ha in New South Wales
alone where it is a declared noxious weed in 14 local government
areas. It contains pyrrolizidine alkaloids that are toxic
to livestock, causing liver damage and stock death. In agricultural
systems, production losses occur due to competition by blue
heliotrope with more desirable cropping and pasture species
and through a decline in animal performance as a result of
its toxicity. This weed is already a serious weed of pastures
and can adversely affect other production systems and natural
ecosystems.
Cultivation encourages spread by stimulation of germination
and regeneration from decapitated rootstocks and plant fragments.
The chemicals currently registered for blue heliotrope have
had limited success and are not selective. Its continued spread
and the increasing rate at which this is occurring indicates
that current control methods are not successful, and it is
considered to be on the verge of becoming a much more serious
problem for agriculture in eastern Australia.
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