Alert List for Environmental Weeds
Department of the Environment and Heritage and the CRC for Australian Weed Management, 2003
ISBN 1 9209 3236 4
About the guide
Siam weed is on the Alert List for Environmental Weeds, a list of 28 non-native plants that threaten biodiversity and cause other environmental damage. Although only in the early stages of establishment, these weeds have the potential to seriously degrade Australia's ecosystems.
Siam weed is recognised as one of the world's worst tropical weeds. It has an extremely fast growth rate (up to 20 mm per day) and prolific seed production. In the tropics of Africa and Asia it is a major pest of crops such as coconuts, rubber, tobacco and sugar cane. Some agricultural areas in South-East Asia have been abandoned because Siam weed has taken over pastures and crops. It is also toxic to stock.
Although only present in Australia in a few small infestations in Far North Queensland, Siam weed could degrade World Heritage-listed rainforests and riverbanks. It also has the potential to increase the fuel load in bushfires, and can cause allergic reactions.