Click on images to enlarge
habit (Photo: Sheldon Navie)
broken stem exuding its milky sap (Photo: Sheldon Navie)
elongated leaves (Photo: Sheldon Navie)
close-up of leaf underside (Photo: Sheldon Navie)
younger leaves and flower buds (Photo: Sheldon Navie)
flower clusters (Photo: Sheldon Navie)
close-up of flowers (Photo: Sheldon Navie)
immature fruit (Photo: Sheldon Navie)
mature fruit releasing their seeds (Photo: Sheldon Navie)
close-up of mature fruit and seeds topped with fluffy hairs (Photo: Sheldon Navie)
close-up of seeds with hairs removed (Photo: Steve Hurst at USDA PLANTS Database)
red-head cotton bush (Asclepias curassavica) is one of the main food plants of the monarch or wanderer butterfly (Danaus plexippus plexippus), a female of which is shown here (Photo: Sheldon Navie)
sparse infestation in a gully at Veresdale near Beaudesert (Photo: Sheldon Navie)
the caterpillars of the monarch butterfly (Danaus plexippus plexippus) are often present on this species (Photo: Sheldon Navie)
Asclepias curassavica L.
Asclepiadaceae (the ACT, Victoria, Tasmania, South Australia, Western Australia and the Northern Territory)Apocynaceae (Queensland and New South Wales)
annual milkweed, bastard ipecac, blood flower, blood-flower, bloodflower, bloodflower milkweed, butterfly weed, false ipecac, Indian root, Mexican milkweed, milkweed, red head cottonbush, redhead, red-head cotton bush, redhead cotton bush, red-head cotton-bush, red-head cottonbush, redhead cottonbush, scarlet milkweed, silkweed, swallow-wort, tropical milkweed
The exact origin of this species is obscure, but it is native to the tropical and sub-tropical regions of the America's.
Widely naturalised in Australia, but most common and widespread in the eastern parts of the country (i.e. in eastern Queensland and the coastal districts of northern New South Wales). Also naturalised in southern and north-western Western Australia, in the north-western parts of the Northern Territory, in southern Victoria, in the coastal districts of central New South Wales and in some parts of eastern and southern South Australia.
This species is regarded as an environmental weed in Queensland and Western Australia. It is a common weed of pastures, disturbed sites, waste areas and roadsides and is also found in natural areas (i.e. wetlands, waterways, open woodlands and grasslands).
Red-head cotton bush (Asclepias curassavica) was recently ranked among the top 200 most invasive plants in south-eastern Queensland, and it is mainly a concern in riparian areas and wetlands in this region. In Western Australia it has been found growing in reasonably intact bushland as well as disturbed urban bushland, from Carnarvon to Mandurah.
Fact sheets are available from Department of Employment, Economic Development and Innovation (DEEDI) service centres and our Customer Service Centre (telephone 13 25 23). Check our website at www.biosecurity.qld.gov.au to ensure you have the latest version of this fact sheet. The control methods referred to in this fact sheet should be used in accordance with the restrictions (federal and state legislation, and local government laws) directly or indirectly related to each control method. These restrictions may prevent the use of one or more of the methods referred to, depending on individual circumstances. While every care is taken to ensure the accuracy of this information, DEEDI does not invite reliance upon it, nor accept responsibility for any loss or damage caused by actions based on it.
Copyright © 2016. All rights reserved. Identic Pty Ltd. Special edition of Environmental Weeds of Australia for Biosecurity Queensland.
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