Numerous plants have been introduced to the state of New South Wales, Australia during the past two centuries, and many of them have become invasive species or noxious weeds which by definition compete with native plants and suppress the growth of indigenous populations. NSW has over 340 weeds, though only one-third are considered noxious, which were purposefully introduced as garden and farmland plants, and thus had escaped. They generally consist of agricultural, scrub, aquatic, roadside and allergenic weeds.
Weeds threaten more than 40% of NSW threatened species (which are predominantly plants) and around 90% of endangered ecological communities. An excess of $50 million of public money (half which come from state government) is currently being spent on weed control. Despite the efforts, the control is not keeping up with their invasiveness, and the NSW Government has granted that it is unlikely to surpass its 2015 goal of ‘a reduction in the impact of invasive species’. [2]
Weeds are threat to the state's natural environment and would jeopardise many native plants and animals in NSW. They would also effect the price of food, human condition (allergies and asthma), recreational activities and the economy of New South Wales. The harmful impact of weeds is increasing fast as more species are introduced and dispersed into new areas. General, state or regional biosecurity duties under the Biosecurity Act 2015 are presented for each weed. [3]
This is the Noxious Weeds Act 1993: [4] [5]
The Biosecurity Act 2015 restricts those that trade or transport plants (called 'priority weeds') that damage the state's environment, economy and community. The restrictions apply to all parts of the plant, such as cuttings, cultivars and hybrids.
'State priority weeds' are banned from being sold in NSW. 'Regional priority weeds' should not be sold or transported in certain regions of NSW. Those that buy or sell them are committing an offence, where they can be issued with hefty penalties. These legal rules apply:
Plants listed below are noxious weeds that should not to be sold in parts of New South Wales due to their invasive nature (most listed here are a 'Weed of National Significance') as they pose a threat to native fauna and flora, and are in the class 3 or 4 categories (a few are prohibited for purchase or propagation in some local government areas). Some of which are widespread weeds, found particularly in disturbed areas, parks and/or house gardens. Some are no longer commonly grown, while others are still cultivated. [8] [9]
Species in bold are common or widespread in the state.
Plants listed below are presently Prohibited Matter in the Biosecurity Act 2015. These plants are banned for importation into NSW and are not yet present in the state. Any person that deals with a Prohibited Matter plant is guilty of an offence. They are generally categorized under Class 1 (state prohibited weeds): [10]
Common name | Scientific name |
---|---|
Anchored water hyacinth | Eichhornia azurea |
Black knapweed | Centaurea x moncktonii |
Bridal veil creeper | Asparagus declinatus |
Broomrapes | Orobanche spp. |
Eurasian water milfoil | Myriophyllum spicatum |
Frogbit | Limnobium laevigatum |
Gamba grass | Andropogon gayanus |
Hawkweed | Hieracium aurantiacum |
Karroo thorn | Vachellia karroo |
Kochea | Bassia scoparia |
Koster's curse | Clidemia hirta |
Lagarosiphon | Lagarosiphon major |
Mexican feather grass | Nassella tenuissima |
Miconia | Miconia spp. |
Mikania vine | Mikania micrantha |
Parthenium weed | Parthenium hysterophorus |
Rubber vine | Cryptostegia grandiflora |
Siam weed | Chromolaena odorata |
Spongeplant | Limnobium spongia |
Spotted knapweed | Centaurea stoebe |
Water caltrop | Trapa spp. |
Water pennywort | Hydrocotyle ranunculoides |
Water soldier | Stratiotes aloides |
Witchweed | Striga spp. |
Yellow burrhead | Limnocharis flava |
Plants listed below are regarded as emerging or significant environmental weeds that are not considered noxious by any state government authorities, even though some are widespread: [11]
Alternanthera philoxeroides, commonly referred to as alligator weed, is a native species to the temperate regions of South America, which includes Argentina, Brazil, Paraguay and Uruguay. Argentina alone hosts around 27 species that fall within the range of the genus Alternanthera. Its geographic range once covered only the Parana River region of South America, but it has since expanded, having been introduced to over 30 countries, such as the United States, Japan, China, Australia, New Zealand and many more. This invasive species is believed to have been accidentally introduced to these non-native regions through sediments trapped by, or attached to, tanks and cargo of ships travelling from South America to these various areas.
A number of introduced species, some of which have become invasive species, have been added to New Zealand's native flora and fauna. Both deliberate and accidental introductions have been made from the time of the first human settlement, with several waves of Polynesian people at some time before the year 1300, followed by Europeans after 1769.
Anredera cordifolia, commonly known as the Madeira vine or mignonette vine, is a South American species of ornamental succulent vine of the family Basellaceae. The combination of fleshy leaves and thick aerial tubers makes this a very heavy vine. It smothers trees and other vegetation it grows on and can easily break branches and bring down entire trees on its own. Other names include lamb's tail and potato vine.
Hygrophila costata, with the common names glush weed, gulf swampweed, and yerba de hicotea, is an aquatic plant.
A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is injurious to agricultural or horticultural crops, natural habitats or ecosystems, or humans or livestock. Most noxious weeds have been introduced into an ecosystem by ignorance, mismanagement, or accident. Some noxious weeds are native. Typically they are plants that grow aggressively, multiply quickly without natural controls, and display adverse effects through contact or ingestion. Noxious weeds are a large problem in many parts of the world, greatly affecting areas of agriculture, forest management, nature reserves, parks and other open space.
Asparagus setaceus, commonly known as common asparagus fern, asparagus grass, lace fern, climbing asparagus, or ferny asparagus, is a climbing plant in the genus Asparagus. Despite its common name, the plant is not a true fern, but has leaves that resemble one.
Asparagus aethiopicus, Sprenger's asparagus, is a plant native to the Cape Provinces and the Northern Provinces of South Africa. Often used as an ornamental plant, it is considered an invasive weed in many locations. Asparagus fern, asparagus grass and foxtail fern are common names; however, it is unrelated to true ferns. A. aethiopicus has been confused with A. densiflorus, now regarded as a separate species, so that information about A. aethiopicus will often be found under the name A. densiflorus.
Cestrum parqui, commonly known as palqui, green cestrum, Chilean cestrum, green poisonberry, or willow-leaved jessamine, is a species of flowering plant native to Chile.
Senecio madagascariensis, also known as Madagascar ragwort, is a species of the genus Senecio and family Asteraceae that is native to Southern Africa. Other common names include Madagascar groundsel and fireweed. It has been included on the noxious weeds list for Hawaii and the reject list for Australia. S.madagascariensis is the diploid cytotype of S.inaequidens.
Ludwigia peploides is a species of flowering plant in the evening primrose family known by the common names floating primrose-willow and creeping water primrose. It is native to Australia, New Zealand, North America, and South America, but it can be found on many continents and spreads easily to become naturalized. It is well known as a troublesome aquatic noxious weed that invades water ecosystems and can clog waterways. This is perennial herb which grows in moist to wet to flooded areas. The stem can creep over 2 meters long, sometimes branching. It spreads to form mats on the mud, or floats ascending in the water. The leaves are several centimeters long and are borne in alternately arranged clusters along the stem. The flower has 5 to 6 lance-shaped sepals beneath a corolla of 5 or 6 bright yellow petals up to 2.4 centimeters long. The fruit is a hard, cylindrical capsule.
Andropogon gayanus, commonly known as gamba grass, Rhodesian blue grass, tambuki grass, and other names, is a species of grass native to most of the tropical and subtropical savannas of Africa.
Ludwigia peruviana, with the common names Peruvian primrose-willow or Peruvian water primrose, is an aquatic, sometimes deciduous species of flowering plant in the evening primrose family. It can grow to approximately 12 feet (3.7 m) in height. While native to Peru, it has been introduced in many other countries for its attractive simple yellow flowers, it is now a common weed in swampy areas around the world.
Nassella tenuissima is a species of grass known by the common names Mexican feathergrass, finestem needlegrass, fineleaved nassella, and Argentine needle-grass. It is native to the south-western United States, northern Mexico and Argentina. It is well-matched to climate in Australia and can be harmful to the Australian environment.
Opuntia rufida is a species of prickly pear cactus native to southwestern Texas and northern Mexico, where it grows on rocky slopes. The species makes up for its total lack of spines with a profusion of red-brown glochids. The common name blind prickly pear or cow blinder comes from the fact that the glochids may be carried away by the wind and blind animals.
An escaped plant is a cultivated plant that has escaped from agriculture, forestry or garden cultivation and has become naturalized in the wild. Usually not native to an area, escaped plants may become invasive. Therefore, escaped plants are the subject of research in invasion biology.
Parts of this Wikipedia article contains material from Weed categories - Plants not to be sold in all or parts of NSW, published by the Government of New South Wales under CC-BY 3.0 AU licence (accessed on 11 March 2021).