Alert List for Environmental Weeds
Department of the Environment and Heritage and the CRC for Australian Weed Management, 2003
ISBN 1 9209 3222 4
About the guide
Blue hound's tongue 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.
Blue hound's tongue is a biennial herb that has been reported to be a problem weed in Argentina and Chile. It could cause problems if it becomes established in Australia as its leaves are toxic to livestock. It was first recorded in Sydney, New South Wales, in 1898. In 1933 a naturalised population was noted in Eden, NSW, and its presence was confirmed until 1976. Two new infestations have been recorded in 2004 upstream from Eden, along the Towamba River. At least one other closely related species, C. officinale (hound's tongue), is a troublesome pasture weed, particularly in Canada and northern central United States. It invades grasslands and suppresses native grasses. Like blue hound's tongue, this plant has burrs that attach to cattle, causing irritation.