Weed Alert: Chinese violet
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- Declared in NSW under the Noxious Weeds Act 1993 (Current Status)
- National Environmental Alert List weed (definition)
Contacts and Further InformationIf you find this weed please contact your local Council Weeds Officer or the nearest NSW Department of Primary Industries office immediately for positive identification and further assistance.
Alternatively call the NSW Weeds Hotline on
1800 680 244 or send an email to firstname.lastname@example.org
Chinese violet (Asystasia gangetica subspecies micrantha)
Chinese violet is a rapidly growing perennial creeper that grows to 1 m high, but can grow over vegetation up to 3 m tall. It is a potentially serious environmental and agricultural weed in Australia as it can completely smother other vegetation, removing habitat, and reducing biodiversity and productivity. This weed grows in tropical and subtropical areas, and is on Australia’s Alert List for Environmental Weeds (28 non-native plants in the early stages of establishment within Australia, identified as a threat to biodiversity).
The subspecies has become invasive in Australia, with its first recording as naturalised made in New South Wales (NSW), at Boat Harbour north of Newcastle in 1999. It is now known to occur in a number of nearby locations, and was found at South West Rocks near Kempsey on the NSW Mid North coast in 2009. These infestations are currently subject to an eradication program and there are no other infestations currently known in NSW.
All infestations in Australia have occurred on coastal sandy soils, but the plant is thought to tolerate a wide range of soil types, preferring full sun or part shade. Plants become spindly in deep shade.
Another commonly cultivated subspecies of Chinese violet (Asystasia gangetica subspecies gangetica), is planted widely in Australia but is less weedy. This subspecies has purple flowers and is naturalised in North Queensland and in the Northern Territory.
Chinese violet is native to India, the Malay Peninsula and Africa. It is a major weed overseas, notably in Malaysia, Indonesia and the Pacific islands, where it infests crops such as rubber and coffee, but particularly oil palm plantations.
Plants spread by seed and plant fragments and can flower and fruit year round.
The seeds are dispersed explosively from the drying fruit capsules. After most of the ripe capsules have released their seeds, the plant dies back to ground level. Winter frosts kill above-ground plant parts but plants regrow the following spring from their basal shoots.
Trailing stems can take root at each node when they come into contact with moist soil. Most infestations in Australia have occurred as a result of dumping garden waste or uncontrolled garden plantings growing into nearby areas.
Chinese violet grows in sprawling mats.
Key identification features
- Leaves and stems have scattered hairs. Leaves are paler beneath and occur in pairs on stems. The leaves are oval shaped, sometimes almost triangular, 2.5 – 16.5 cm long and 0.5 – 5.5 cm wide.
- White bell-shaped flowers are 2 – 2.5 cm long, with characteristic purple blotches in two parallel lines inside.
- Fruit capsules are 3 cm long, guitar-shaped (with the neck of guitar attached to stem) and contain four flattened seeds held in place by conspicuous hooks.
Your local council weeds officer will assist with identification, control information and removal of this weed. Infestations can be spread by inappropriate control activities. New infestations can develop from any rhizomes that are moved or dropped during control activities. Early detection and eradication will prevent the spread of this weed.
Chinese violet is a Class 1 State Prohibited Weed across NSW under the Noxious Weeds Act 1993. It must be eradicated and land must be kept free of the plant. As a notifiable weed, all outbreaks must be reported to the local council within 24 hours, and the plant is prohibited from sale in NSW.
Written by Peter Gorham and John Hosking 2003; 2012 edition reviewed by Rod Ensbey; Edited and prepared by Elissa van Oosterhout and Birgitte Verbeek.
References: Chinese violet Weed Management Guide (2003) Weed Management CRC.