Yellow Gromwell

Amsinckia calycina, also known as hairy fiddleneck or yellow burweed, is a species of fiddleneck. It is native to Argentina and Chile and naturalised in Australia. It is an annual herb, growing to between 15 and 50 cm high and has pale yellow flowers. The species is poisonous to mammals

Hairy fiddle-neck (Amsinckia calycina) is a weed of disturbed sites and cultivated land, particularly winter cereal crops, in many parts of Australia. In the south-eastern parts of the country, where it is most abundant, it also invades pastures and natural habitats.

It is sometimes regarded as an environmental weed in Victoria and appears on some local and regional weed lists in this state (e.g. in Mornington Peninsula Shire and the Goulburn Broken Catchment). Hairy fiddle-neck (Amsinckia calycina) is also listed as a highly invasive and high impact weed species in plains grassland communities in the Lowan Mallee bioregion.

Fiddle-necks (Amsinckia spp.) are also reported to be invasive in intact native vegetation in south-eastern South Australia, with a moderate potential to reduce native species diversity. They are said to produce dense and persistent stands, and can only be controlled with sustained effort. As hairy fiddle-neck (Amsinckia calycina) is currently the only fiddle-neck species  (Amsinckia sp.) thought to occur in South Australia, it is most likely the cause of these concerns.

While it is generally not regarded as an environmental weed in other states, hairy fiddle-neck (Amsinckia calycina) has been recorded in natural areas in southern New South Wales (e.g. in Kinchega National Park and in sub-alpine and alpine areas of the Australian Alps) and grassland areas in Tasmania.