# List of invasive plant species in the Northern Territory

Numerous plants have been introduced to the Northern Territory of Australia since colonisation began in the 1860s. Many have become invasive species or noxious weeds which by definition compete with native plants and suppress the growth of indigenous populations of both plants and animals.
A weed is broadly considered to be a plant that requires some form of action to reduce its negative effects on the economy, the environment and human health or amenity. XXX weeds are declared under legislative controls to reduce their impacts.

## Weed classification

The Weeds Management Act 2001 defines three classes of weeds:
* Class A: to be eradicated
* Class B: control, growth and spread to be prevented
* Class C: prevent entry, not to be introduced into the Northern Territory
All class A and class B weeds are also included as class C weeds.

## Lists
### Declared weeds

| Botanical name | Common name | Declaration class |
| Alternanthera philoxeroides | Alligator weed | A |
| Andropogon gayanus | Gamba grass | A, B |
| Annona glabra | Pond apple | A |
| Asphodelus fistulosus | Onion weed | A |
| Austrocylindropuntia spp. | Opuntioid cacti | A |
| Barleria prionitis | Barleria | A |
| Cabomba spp. | Cabomba | A |
| Chrysanthemoides monilifera | Bitou bush, boneseed | A |
| Cryptostegia spp. | Rubber vines | A |
| Cylindropuntia spp. | Opuntioid cacti, rope cacti | A |
| Dalbergia sissoo | Longspine thornapple | A |
| Datura ferox | Dalbergia | A |
| Dolichandra unguis-cati syn. Macfadyena unguis-cati | Cat's claw creeper | A |
| Echium plantagineum | Paterson's curse | A |
| Eichhornia crassipes | Water hyacinth | A |
| Hyparrhenia rufa | Thatch grass | A |
| Jatropha curcas | Physic nut | A |
| Jatropha gossypiifolia | Bellyache bush | A, B |
| Lycium ferocissimum | African boxthorn | A |
| Martynia annua | Devil's claw | A |
| Mimosa pigra | Mimosa | A, B |
| Myriophyllum aquaticum | Parrot's feather | A |
| Nassella neesiana | Chilean needle grass | A |
| Nassella tenuissima | Mexican feather grass | A |
| Nassella trichotoma | Serrated tussock | A |
| Neptunia plena | Water mimosa | A |
| Neptunia oleraceae | Water mimosa | A |
| Opuntia spp. | Prickly pears | A |
| Parthenium hysterophorus | Parthenium weed | A |
| Pereskia aculeata | Leaf cactus | A |
| Prosopis spp. | Mesquite | A |
| Rubus fruticose agg. | Blackberry | A |
| Sagittaria platyphylla | Sagittaria | A |
| Salix spp. | Willows | A |
| Schinus terebinthifolius | Brazilian pepper | A, B |
| Senegalia catechu syn. Acacia catechu | Cutch tree | A |
| Tamarix aphylla | Athel pine | A, B |
| Ulex europaeus | Gorse | A |
| Vachellia nilotica syn. Acacia nilotica | Prickly acacia | A |
| Ziziphus mauritiana | Chinee apple, Indian jujube | A |
| Acanthospermum hispidum | Star burr, goat’s head | B |
| Alternanthera pungens | Khaki weed | B |
| Argemone ochroleuca | Mexican poppy | B |
| Azadirachta indica | Neem | B |
| Calotropis procera | Rubber bush | B |
| Carthamus lanatus | Saffron thistle | B |
| Cenchrus echinatus | Mossman River grass | B |
| Cenchrus polystachios Syn. Pennisetum polystachion | Mission grass (perennial) | B |
| Cenchrus setaceus | Fountain grass | B |
| Emex australis | Spiny emex | B |
| Hymenachne amplexicaulis | Olive hymenachne | B |
| Hyptis capitata | Knob weed | B |
| Hyptis suaveolens | Hyptis | B |
| Lantana camara | Common lantana | B |
| Lantana montevidensis | Creeping lantana | B |
| Leonotis nepetifolia | Lion's tail | B |
| Mimosa pudica | Common sensitive plant | B |
| Parkinsonia aculeata | Parkinsonia | B |
| Pistia stratiotes | Water lettuce | B |
| Ricinus communis | Castor oil plant | B |
| Salvinia molesta | Salvinia | B |
| Senna alata | Candle bush | B |
| Senna obtusifolia | Sicklepod | B |
| Senna occidentalis | Coffee senna | B |
| Sida acuta | Spinyhead sida | B |
| Sida cordifolia | Flannel weed | B |
| Sida rhombifolia | Paddy's lucerne | B |
| Stachytarpheta spp. | Snake weeds | B |
| Themeda quadrivalvis | Grader grass | B |
| Tribulus cistoides | Caltrop | B |
| Tribulus terrestris | Caltrop | B |
| Xanthium strumarium Syn. Xanthium occidentale | Noogoora burr | B |
| Xanthium spinosum | Bathurst burr | B |
| Acroptilon repens | Creeping knapweed | C |
| Ageratina riparia | Mistflower | C |
| Amaranthus dubius | Chinese spinach | C |
| Ambrosia artemisiifolia | Annual ragweed | C |
| Ambrosia psilostachya | Perennial ragweed | C |
| Anredera cordifolia | Madeira vine | C |
| Asparagus asparagoides | Bridal creeper | C |
| Asparagus scandens | Asparagus fern | C |
| Asparagus declinatus | Bridal veil | C |
| Asparagus aethiopicus | Ground asparagus | C |
| Asparagus africanus | Climbing asparagus | C |
| Asparagus plumosus syn. Asparagus setaceus | Climbing asparagus ferm | C |
| Austroeupatorium inulaefolium | Austroeupatorium | C |
| Baccharis halimifolia | Groundsel bush | C |
| Boerhavia erecta | Erect spiderling | C |
| Brachiaria paspaloides | Common signal grass | C |
| Chromolaena odorata | Siam weed | C |
| Clidemia hirta | Koster's curse | C |
| Coix aquatica | Job's tears | C |
| Croton hirtus | Hairy croton | C |
| Cytisus scoparius | Scotch broom | C |
| Datura spp. | Thornapples | C |
| Digitaria fuscescens | Common crabgrass | C |
| Digitaria insularis | Sourgrass | C |
| Diodia sarmentosa | Tropical buttonweed | C |
| Echinochloa glabrescens | Barnyard grass | C |
| Echinochloa stagnina | Burgu millet | C |
| Egeria densa | Dense waterweed | C |
| Elodea canadensis | Canadian pondweed | C |
| Equisetum spp. | Horsetails | C |
| Eriocaulon truncatum | Short pipewort | C |
| Eriocereus martinii | Harrisia cactus | C |
| Eriochloa polystachya | Carib grass | C |
| Fimbristylis umbellaris | Globular fimbristylis | C |
| Genista linifolia | Flax-leaved broom | C |
| Genista monspessulana | Montpellier broom | C |
| Hybanthus attenuatus | Western greenviolet | C |
| Hyptis brevipes | Lesser roundweed | C |
| Ischaemum timorense | Centipede grass | C |
| Kochia scoparia syn. Bassia scoparia | Burning bush | C |
| Lagarosiphon major | Lagarosiphon | C |
| Leptochloa chinensis | Red sprangletop, feathergrass | C |
| Leptochloa panicea | Sprangletop | C |
| Limnobium laevigatum | Amazon frogbit | C |
| Limnocharis flava | Yellow burrhead, yellow sawah lettuce | C |
| Miconia spp. | Velvet tree | C |
| Mikania cordata | Heartleaf hempvine | C |
| Mikania micrantha | Mikania, mile-a-minute | C |
| Mimosa invisa | Giant sensitive plant | C |
| Myriophyllum spicatum | Eurasian watermilfoil | C |
| Orobanche spp. | Broomrapes | C |
| Paederia foetida | Lesser Malayan stinkwort | C |
| Piper aduncum | Spiked pepper | C |
| Rhodomyrtus tomentosa | Downy rose myrtle | C |
| Rotala indica | Indian toothcup | C |
| Sacciolepis interrupta | Cupscale grass | C |
| Salvinia cucullata | Salvinia | C |
| Salvinia natans | Salvinia | C |
| Schoenoplectus juncoides | Rock bulrush | C |
| Scirpus maritimus Syn. Bolboschoenus maritimus | Sea clubrush | C |
| Senecio madagascariensis | Fireweed | C |
| Solanum elaeagnifolium | Silver leaf nightshade | C |
| Sorghum halepense | Johnson grass | C |
| Spermacoce mauritiana syn. Spermacoce exilis | Pacific false buttonweed | C |
| Striga spp. | Witchweeds | C |
| Trapa spp. | Floating water chestnuts | C |
| Xanthium spp. | Burrs | C |
| Cenchrus ciliaris | Buffel grass | Yet to be declared |