Ecological weeds on conservation land in New Zealand


This page lists weeds of concern on conservation land in New Zealand (with references).

This list is from: Owen, S.J. 1996. Ecological weeds on conservation land in New Zealand: a database. 118p. Department of Conservation, Wellington.

Other weeds recognized as potential problems at the time of publication of the printed version are listed separately. Many of these weeds are now subject to control.

An updated list will be produced sometime in the near future. This list is put out as it was found in the 1996 publication. If you have any comments, send them to Chris Buddenhagen (cbuddenhagen@doc.govt.nz).

A printed version of this is available from:

PHONE: 64-4-471-3136 FAX: 64-4-471-3279

E-mail: svaughan@doc.govt.nz

Weeds of concern on conservation lands in New Zealand
Botanical nameSpecies common nameLit. RefGrowth formyear of naturalisation in NZCountry/area of origin
Acacia dealbatumsilver wattle2,3,10Tree (6-10m)1870E Australia
Acacia longifoliumSydney golden wattle2,12Tree (6-10m)1897E Australia
Acacia paradoxumkangaroo acacia2Tree (<6m)1911W & E Australia
Acer pseudoplatanussycamore8, 12Tree (>10m)1880C & S Europe
Acmena smithiimonkey apple Tree (>10m)1982E.Australia
Agapanthus praecoxagapanthus11Bulb herbs1952Sth Africa
Ageratina adenophoraMexican devil1,3Erect herb1931Mexico
Ageratina ripariamist flower1Erect herb1931Mexico, W. Indies
Agrostis capillarisbrowntop Grass1867Europe, temp. Asia
Allium triquetrumonion weed11Bulb herbs1899SW Europe, N Afr.
Alnus glutinosaalder Tree (>10m)1914Eurasia, N Africa
Alocasia brisbanensiselephant's ear12Bulb herbs1867trop Asia
Alternanthera philoxeroidesalligator weed2,11,12Aquatic1906Brazil
Ammophila arenariamarram2, 12Grass1873Europe, Nth Africa
Anredera cordifoliamadeira vine2,11,12Vine1940trop S America
Araujia sericiferamoth plant Vine1888S Brazil, Argentina
Aristea eckloniiaristea Bulb herbs1975trop & S Africa
Arrhenatherum elatiustall oat grass Grass1871Eurasia, Nth Africa
Arum italicumItalian lily Bulb herbs1945Eurasia
Arundo donaxgiant reed3Grass1936Eurasia
Asparagus asparagoidessmilax2Vine1905trop & S Africa
Asparagus scandensclimbing asparagus2Vine1970trop & S Africa
Berberis darwiniiDarwin's barberry11Tree (<6m)1946S. Chile, Argentina
Berberis glaucocarpabarberry Tree (6-10m)1916W Himalaya
Bromus tectorumcheatgrass, downy brome1, 12Grass1870Mediterranean
Buddleja davidiibuddleia8Shrub (3-5m)1946China
Caesalpinia decapetalaMysore thorn1,3,12Tree (6-10m)1965India
Calluna vulgarisheather Shrub (<3m)1910Eurasia, N Africa
Carduus nutansnodding thistle Bi/Annual1889Eurasia, N Africa
Carex longebrachiataAustralian sedge Rush1906Australia
Celastrus orbiculatusclimbing spindleberry Tree (6-10m)1981NE temp Asia
Cestrum aurantiacumorange cestrum Shrub (<3m)1958Guatemala
Cestrum elegansred cestrum2Shrub (3-5m)1958Mexico
Chrysanthemoides moniliferabone seed2Shrub (3-5m)1870S Africa
Cirsium spp.thistles2Bi/Annual1870Eurasia
Clematis flammulaclematis Vine1968Eurasia, N Afr.
Clematis vitalbaold man's beard2Vine1940Europe, SW Asia
Cobaea scandenscathedral bells Vine1946C & S America
Convolvulus arvensisconvolvulus, field bindweed10Vine1880N temperate
Cortaderia jubatapurple pampas4, 5Grass1965America
Cortaderia selloanapampas2,5Grass1925America
Cotoneaster glaucophylluscotoneaster2Shrub (3-5m)1982China
Cotoneaster simonsiiKhasia berry Shrub (3-5m)1958Burma
Crataegus monogynahawthorn2,10Tree (6-10m)1899Europe
Crocosmia x crocosmiifloramontbretia2Bulb herbs1935trop S America
Cytisus scopariusbroom2Shrub (<3m)1872Eurasia
Dactylis glomeratacocksfoot12Grass1867Eurasia, Nth Africa
Dipogon lignosusmile-a-minute2Vine1871S Africa
Echium vulgareviper's bugloss10,11Bi/Annual1870Eurasia
Egeria densaegeria Aquatic1946sub-trop America
Ehrharta erectaveld grass2Grass1944Sth Africa
Ehrharta villosapyp grass2Grass1990Sth Africa
Elaeagnus x reflexaelaeagnus Vine1940?Japan
Equisetum arvensehorsetail Fern1922N temperate
Erica lusitanicaSpanish heath2, 12Shrub (<3m)1926SW Europe
Erigeron karvinskianusMexican daisy Mat forming1940Mexico
Eriobotrya japonicaloquat1Tree (<6m)1982China, Japan
Euonymus europaeusspindleberry Tree (<6m)1958Europe
Euonymus japonicusJapanese spindleberry2Tree (6-10m)1980Jap, China, Korea
Festuca arundinacea  Grass1871
Glyceria fluitansfloating sweetgrass Grass1872almost cosmopolitan
Gymnocoronis spilanthoidesSenegal tea Aquatic 
Hakea gibbosahakea, downy Tree (<6m)1937NSW
Hakea salicifoliahakea, willow-leaved2Tree (<6m)1908E Australia
Hakea sericeahakea, prickly2,3,12Tree (<6m)1883Tas., E Australia
Hedera helixivy1,2Vine1873temp. Europe, Asia
Hedychium flavescensyellow ginger1, 12Erect herb1898Himalayas
Hedychium gardnerianumkahili ginger1, 12Erect herb1940India
Hieracium spp.hawkweed Mat forming1878Europe
Humulus lupulushops11Vine1872Europe, C&W Asia
Hydrilla verticillatahydrilla1, 12Aquatic1963Eurasia
Hydrodictyon reticulatumwater net Aquatic1986Eurasia
Hypericum androsaemumtutsan2Shrub (<3m)1870S & W Europe
Hypericum perforatumSt John's wort2, 5Erect herb1869Eur, W Asia, N Afr
Ipomoea indicablue morning glory1, 11Vine1950pantropical
Iris foetidissimastinking iris Bulb herbs1945Europe & N Afr
Iris pseudacorusyellow flag iris11Bulb herbs1938Eur, Asia, N Afr
Jasminium humileyellow jasmine Shrub (<3m)1958temp Himalaya, SW China
Jasminum polyanthumjasmine Vine1980W China
Juglans ailantifoliaJapanese walnut Tree (>10m)1983Japan
Juncus acutussharp rush2, 11Rush1923Europe, Africa, N Am
Juncus articulatusjointed rush11Rush1864Eurasia, N Am, N Africa
Juncus bulbosusbulbous rush11Rush1896Eurasia, N Africa
Juncus effusussoft rush2Rush1864Eurasia
Juncus squarrosusheath rush Rush1910Eur, N Afr, Iceland
Lagarosiphon majorlagarosiphon12Aquatic1950trop & S Africa
Lantana camara var. aculeatalantana1,6Shrub (<3m)1912trop America
Leycesteria formosaHimalayan honeysuckle2Shrub (<3m)1878temp Himalaya
Ligustrum lucidumtree privet2,12Tree (>10m)1958China, Korea
Ligustrum sinenseChinese privet2Tree (<6m)1950China
Lolium perenneperennial ryegrass Grass1855Eur, temp Asia, N Afr
Lonicera japonicaJapanese honeysuckle1,2,12Vine1926E Asia
Lotus pedunculatuslotus Mat forming1867Europe, Asia, N Afri
Lupinus arboreustree lupin1,2Shrub (<3m)1899California
Lupinus polyphyllusRussell lupin1,11Erect herb1958N America
Lycium ferocissimumboxthorn2Shrub (<3m)1897S Africa
Melianthus majorCape honey flower Shrub (<3m)1878S Africa
Mimulus guttatusmonkey musk8Shrub (<3m)1878N America
Myriophyllum aquaticumparrot's feather12Aquatic1970S. America
Nephrolepis cordifoliatuber sword fern Fern1974pantropic
Olea europaea subsp cuspidataAfrican olive Tree (<6m)1977E Afr to S Afr
Osmunda regalisroyal fern Fern1890Eur, W&S America
Oxylobium lanceolatumoxylobium2Tree (<6m)1931W Australia
Pandorea pandoranawonga wonga vine Vine1981N Guinea, E Australia
Paraserianthes lophanthabrush wattle1,2,3Tree (<6m)1870W Australia
Paspalum distichumMercer grass Grass1906Europe
Passiflora edulisblack passionfruit1,3Vine1950trop America
Passiflora mixtanthn banana passionfruit1Vine1970N Andes
Passiflora mollissimabanana passionfruit1,12Vine1958trop S America
Pennisetum clandestinumKikuyu grass1,2Grass1936E. Africa
Pennisetum macrourumAfrican feather grass Grass1940trop. & Sthern Africa
Pennisetum setaceumAfrican fountain grass1,12Grass1982NE Africa
Phytolacca octandrainkweed11Shrub (<3m)1867trop C&S America
Pinus contortalodgepole pine Tree (>10m)1957NW America
Pinus spp. incl mugo, contorta, pinaster, radiatawilding pine1Tree (>10m)various
Polygala myrtifoliasweet pea bush1,2Shrub (<3m)1870S Africa
Populus albawhite poplar11Tree (>10m)1904Eurasia. Africa
Prunus aviumsweet cherry Tree (6-10m)1872Europe
Pseudotsuga menziesiiDouglas fir Tree (>10m)1925N America
Psoralea pinnatadally pine2Shrub (3-5m)1870S Africa
Pyracantha angustifoliaorange firethorn11Shrub (3-5m)1958China
Reynoutria japonicaJapanese knotweed7Erect herb1935Japan
Reynoutria sachalinensisgiant knotweed7Erect herb1935E Asia, N Japan
Rhamnus alaternusevergreen buckthorn2Shrub (3-5m)1940Mediterranean
Rosa rubiginosasweet briar10,12Shrub (<3m)1867Europe
Rubus fruticosus agg.blackberry1,2Vine1867N temperate
Rumex sagittatusclimbing dock Vine1935S Africa
Salix cinereagrey willow2Tree (6-10m)1925Eur, W Asia, N Africa
Salix fragiliscrack willow2Tree (6-10m)1880Europe, W Asia
Salvinia molestasalvinia, water fern12Aquatic1964sub/tropical widely
Sambucus nigraelder / elderberry Tree (>10m)1867Eur, W Asia, N Africa
Sedum acrestone crop Mat forming1904Eur, W Asia, N Africa
Selaginella kraussianaselaginella11Fern1919C&S Africa
Senecio angulatusCape ivy11Vine1940S Africa
Senecio jacobaearagwort2Bi/Annual1894Europe, W Asia
Senecio mikanioidesGerman ivy1,10Vine1870S Africa
Senna septemtrionalisbuttercup bush Shrub (3-5m)1965Mexico, C America
Setaria palmifoliapalmgrass1Erect herb1981India
Solanum jasminoidespotato vine Vine1958S Brazil
Solanum linnaeanumapple of Sodom11Shrub (<3m)1883N Africa
Solanum mauritianumwoolly nightshade3, 12Tree (<6m)1883S Brazil, Uruguay
Solanum pseudocapsicumJerusalem cherry1Shrub (<3m)1935Eastern Sth America
Sorbus aucupariarowan11Tree (>10m)1904Eurasia
Spartina alternifloraAmerican spartina Grass1965N. America
Spartina anglicaspartina 2,12Grass1981England
Spartina x townsendiispartina hybrid2Grass1924England
Stipa neesianaChilean needlegrass2Grass1940S. America
Stipa trichotomanassella tussock1,3,12Grass1931S. America
Syzygium australebrush cherry Tree (6-10m)1982Qld, NSW
Teline monspessulanaMontpellier broom2, 10Shrub (<3m)1872Meditrn, Asia Minor, Azores
Tradescantia fluminensiswandering Jew12Mat forming1916Brazil
Tropaeolum majusnasturtium1Bi/annual1883N. Andes
Tropaeolum speciosumChilean flame creeper Vine1958Chile
Tussilago farfaracoltsfoot Erect herb1975Eur, N Afr, N&W Asia
Ulex europaeusgorse1,2,12Shrub (3-5m)1867W Europe
Vaccinium corymbosablueberry Shrub (<3m)1988N America
Vinca majorperiwinkle2Erect herb1870E&C mediterranean
Watsonia bulbilliferawatsonia2Bulb herbs1895S Africa
Zantedeschia aethiopicaarum lily2Bulb herbs1870Sth Africa
Zizania latifoliaManchurian rice grass Grass1906Asia
Number of species: 164


References

1 Stone, P.C., Smith, C.W., and Tunison, J.T. (eds) (1992)

Alien Plant Invasions in Native Ecosystems of Hawaii: Management and Research Univ. of Hawaii Press, Honolulu

2 Humphries, S.A., Groves, R.H. and Mitchell, D.S. (eds) (1991)

Plant Invasions of Australian Ecosystems: A Status Review and Management Directions Kowari 2:1-136 Australian National Parks and Wildlife Service Publications, Canberra

3 Macdonald, I.A.W., Kruger, F.J. and Ferrar, A.A. (eds) (1986)

The Ecology and management of Biological Invasions in South Africa Oxford Univ. Press, Cape Town

4 Beerling, D.J. and Perrins, J.M. (1993)

Impatiens glandulifera (syn Impatiens roylei): Biological Flora of the British Isles Journal of Ecology 81:367-382

5 Mooney, H.A. and Drake, J.A. (eds) (1986)

Ecology of Biological Invasions in North America and Hawaii

6 Ramakrishnan, P.S. (ed) (1991)

Ecology of Biological invasions in the Tropics International Science Publications, New Delhi

7 Thomson, A.G, Radford, G.L., Norris, D.A. and Good, JEG (1993)

Factors affecting the spread and distribution of Rhododendron in north Wales Journal of Environmental Management 39:199-212

8 Gray, A.J. and Crawley, M.J. (eds) (1987)

Colonisation, Succession and Stability 26th British Ecological Society Symposium, Blackwell, London

9 Brothers, T.S. and Spingarn, A. (1992)

Forest fragmentation and alien plant invasion of Central Indiana old-growth forests Conservation Biology 6:91-100

10 Groves, R.H. and di Castri, F. (eds) (1991)

Biogeography of Meditteranean Invasions Cambridge University Press, Cambridge

11 Carr, G.W., Yugovic, J.V. and Robinson, K.E. (1992)

Environmental weed invasions in Victoria. Dept. of Conservation and Environment, Melbourne.

12 Cronk, Q.C.B., and Fuller, J.L. (1995)

Plant Invaders: The threat to natural ecosystems Chapman and Hall


Weeds Recognized as Potential Problems in New Zealand (as of 1996)
Botanical nameCommon nameGrowth form year of naturalisation in NZCountry/area of origincountry in which species is plant pestnotes
Agave americanacentury plant 1869Mexico Local weed - vegetatively spreads through dunes (Ewen Cameron 1996) Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). In Weed Control operational plan for Rangitoto, 1996.
Albutilon darwinii x A. pictumChinese lanternShrub (<3m)1981cultivated hybrid Invading forest edges & forms thickets. A few infestations looking very weedy. Possibly in lag phase. (Lisa Forester, 1996). Minor around Auckland (Ewen Cameron, 1996)
Andropogon virginicusbroomsedgeGrass1976N & C Am, W IndiesHawaii, AustraliaDense cover in disturbed grassland/scrub.
Arctotheca calendulaCape weed 1870Sth Africa Widely distributed in NZ (Flora IV). Poisonous. Poor pasture weed, or in coastal, sandy situations (Ewen Cameron & Carol West 96)
Asparagus densiflorusbushy asparagus    Lord Howe Is.Already naturalised in 3-4 places in Auckland (Ewen Cameron 1996)
Azolla pinnataferny azollaAquatic1969trop. Africa, Asia, Australia Floating fern. Has replaced a native floating fern Azolla rubra, over most of northern NZ (Ewen Cameron, 1996)
Banksia integrifoliabanksia mid 1980sAustralia First naturalised mid-1980's. Naturalised commonly by 90's. Threat to well drained sites, e.g. stabilised dunes. (Ewen Cameron, 1996)
Bartlettina sordidabartlettinaShrub (<3m)1984Mexico Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Whangarei, Auckland, Lower Hutt - locally established as escape from cultivation (Flora IV). So far mainly forest margins where stands out at foreign (Ewen Cameron 1996)
Brachiairia muticapara grass 1977N&W trop. Africa Listed as a weed for eradication on Raoul Island but not likely to have a long term significant impact. One patch - only known infestation in NZ.
Bryonia dioica white bryony    Soft vine. Spreading in Makino Scenic Reserve on the Rangitikei River (Wanganui). Only NZ record so far, but looks to be spreading (via birds). (Colin Ogle 1997)
Canna indicaIndian shot 1870West Indies, C&S America Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Usually spreads vegetatively rather than by seed; problem where its been allowed to spread over long time period (Ewen Cameron 1996).
Cardiospermum spp.balloon vineVinenot yet Aust, Sth Afr, PacificNot yet seen naturalised but cultivated widely. (Lisa Forester, 1996). Potential weed given overseas experience? (Ewen Cameron 1996).
Carex flaccacarnation sedge 1883Europe, N. Asia, N. Africa Serious problem in Travis wetland, Christchurch. Dense, smothering ground cover, excludes natives. Seed & rhizome. Potential wetland threat. Young plants distinctively blue-grey. (Melanie Newfield, 1996). Not yet a threat in Auckland area (Cameron 1996).
Ceratophyllum demersumhornwort 1969cosmopolitan Widespread in lakes, rivers or wetlands. Can be free-floating or rooted. (Chris Richmond, 1997)
Cestrum nocturnumqueen of the night 1980W Indies, C America Naturalised in Auckland, Northland and BoP. Wasteland and scrub. Poisonous. Spreading into native bush where hard to distinguish from natives (Ewen Cameron 1996). Potential as serious eco. weed (Carol West 96)
Cestrum parquigreen cestrumShrub (<3m)1908Warm temp S Am Naturalised in one place in Auckland only & hard to kill (Ewen Cameron '96). Potential as serious ecological weeds (Carol West '96). Scrub, riparian. Frost resistant. Poisonous.
Clematis tanguticaChinese clematis 1958? In shrublands around the Clutha Valley, Otago, where it is spreading slowly. A potentially significant weed - should be watched (Colin Ogle, Brian Patrick, '97); Note: the species is probably C. tibetana (Colin Ogle)
Crassula multicavapitted crassula 1959Sth Africa Establishing northern coastal cliffs, Little Barrier, where it is very bad - potential nasty (Ewen Cameron 1996). Invades bare ground, rock. Spreads vegetatively to form dense cover - plantlets on flower heads drop off & develop.
Cyathea cooperitree fernFern1993 HawaiiCultivated in Auckland for 15 years. So far only one wild record (which is in the open). Hard to distinguish from natives - possible it might hybridise? (Ewen Cameron, 1996)
Cynodon dactylonIndian doab 1846Pantropical Widespread grass in warmer parts of NZ; may be a threat in species places with rare, low-growing communities (Carol West). Minor problem back of beaches, but Kikuyu & buffalo grass far worse (Ewen Cameron 1996).
Echium plantagineumPaterson's curse 1880Med nth to Sth EnglandAustraliaNot really a threat to natural areas ? (Ewen Cameron 1996). Wasteland, pastures. Poisonous. North Is especially north of volcanic plateau. Rare in northern South Is.
Ehrharta longifoliaannual veld grassGrass1989Sth Africa Wanganui only. Annual (Sept to Nov.). Tufted; in gardens, sandy soils. (Colin Ogle, Wanganui Conservancy, 21/8/96)
Elodea canadensisCanadian pondweed 1916N AmericaC Eur, UK, NSWListed as naturalised in Auckland (Dick Veitch, 1995). Not a major problem in Auckland where Egeria is main pest (Ewen Cameron 1996); but suppresses natives in lakes/rivers where it has not been replaced by egeria (eg L. Waikaremoana) (Chris Richmond '97)
Equisetum hyemalerough horsetail    Rhizomes to 1m underground. Toxic to stock. Aggressive & almost impossible to eradicate. Being sold & given away as medicinal herb. Slender asparagus-like spear with black rings. (Melanie Newfield, 1996). Major potential weed.
Eragrostis curvulaAfrican love grassGrass1969Africa 1 m tall. Invading in Northland and Three Kings Islands. (Lisa Forester, 1996). Potential major weed (Carol West 1996).
Erythrina x sykesiicoral tree 1986cultivated hybrid Cuttings & dropped branches take root easily. Dense thickets can form. A major problem in wetlands of some Northland areas. Listed in Little Barrier Is. Weed control operational plan, 1996. However sterile, and easily controlled. (Forester, West, Cameron)
Eucalyptus botryoidesblue gum 1957d valign="top">New Sth Wales, Victoria Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Never seen gums as a major weed (Ewen Cameron 1996); but may just be seeing a very early lag phase (Carol West 1996).
Eucalyptus globulusTasmanian blue gum 1880Tasmania Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Never seen gums as a major weed (Ewen Cameron 1996); but may just be seeing a very early lag phase (Carol West 1996).
Eucalyptus salignaSydney blue gum 1957NSW, Queensland Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Never seen gums as a major weed (Ewen Cameron 1996); but may just be seeing a very early lag phase (Carol West 1996).
Ficus macrophyllaMoreton Bay figTree (>10m)1995Australia Pollinator recently arrived in NZ. First seedling seen Auckland 1995. One to watch, but evidence suggests won't be as aggressive as F. rubiginosa (Ewen Cameron, 1996).
Ficus microcarpa  not yet see note  Not yet naturalised - still lacks pollinator. Occasionally cultivated in NZ. One to watch. (Ewen Cameron, 1996).
Ficus pumilacreeping fig 1981Japan, China Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Can't set seed but can climb; not seen as a problem yet (Ewen Cameron 1996).
Ficus rubiginosaPort Jackson fig 1981NSW, Queensland Pollinator arrived 20 years ago. Potential pest only in special places, e.g. Rangitoto island. (Ewen Cameron, 1996)
Furcraea foetidaMauritius hemp 1966S. America, Brazil Being eradicated on Raoul Island as considered to be able to significantly affect indigenous community in long term. Also a problem on foreshore of Kawau Island, though can't spread quickly (Ewen Cameron 1996).
Galeobdolon luteumaluminium plant 1988Europe, W. Asia Can cover large areas of ground in open and semi-shaded areas. Listed in Little Barrier Is. Weed control operational plan, 1996. Spreads rapidly - one to watch (Ewen Cameron 1996).
Glyceria maximareed sweetgrassAquatic1906EuropeAustraliaSemi-aquatic grass; grows in slow moving streams, drains. (Carol West 21/8/96), and a major ecological weed in wetlands (Ewen Cameron 1996). Forms dense monoculture in fertile sites. Effective nutrient stripper in artificial wetlands. (Chris Richmond '97)
Gunnera tinctoriaChilean rhubarb 1968Sth America (Andes) Megaherb; planted widely in NZ. In wet places, seepages, riverbanks; & on wet/clay seacliffs. Very invasive along several km of banks of Oanui River, & spreading quickly in Wanganui region. (Colin Ogle 1997)
Homalanthus populifoliusQueensland poplar 1980NSW to New Guinea Bird dispersed. Shade tolerant & invades broad range of habitats. (Lisa Forester, 1996). Major ecological weed (West, Cameron 1996). Common in Auckland city (Cameron 1996)
Homeria collinaCape tulip 1944Sth Africa Listed as class A noxious weed - but more as is toxic than for any environmental impacts (Ewen Cameron 1996).
Houttuynia cordata var. chameleonvar. chameleonAquaticNot yet. see noteAsian.USA, AsiaIntroduced 1990, not yet naturalised. A MAF notifiable plant. Ground cover; up to 1m tall; rhizomes. Seeds with or without fertilisation. Tolerates submerged or dry. (Paul Champion, NIWA, 14/8/96)
Impatiens sodeniishrub balsam 1958E. Africa Forms dense thickets. Grows well from seeds & cuttings. Listed in Little Barrier Is. and Rangitoto Is. Weed control operational plans, 1996. Potential to be bad eco. weed - is becoming more common on bush margins, rank grasses etc. (Ewen Cameron 1996).
Imperata cylindrica var. majorcogon grass, bladey grassGrass1911trop/warm temp Asia, Aust, New C., E. Afr, Lord Howe Dense swards. (Lisa Forester, 1996)
Larix decidualarch 1919Europe, W Asia Aggressive in the MacKenzie Basin (Shannel Courtney, DoC Nelson 21/8/96) and in Central Otago.
Lythrum salicariapurple loosestrifeAquatic1958Eur, W Asia, Nth AfrUSA, AustraliaLake margin, wetland. Up to 3m. Each plant up to 50 stems. 2.5 million seeds/plant. Seeds viable up to 3 years. (Paul Champion, NIWA, 14/8/96)
Malvaviscus arboreus var. arboreusTurk's cap 1981Trop & sub-trop Am Shade tolerant. Spread by layering. (Inf.: Lisa Forester, DoC Northland, 14/8/96). Have seen fruit; potential significant weed (Ewen Cameron 1996).
Miscanthus nepalensisHimalayan fairy grassGrass1946Nepal/India Invading forest margins, bluffs. (Lisa Forester,1996). Large problem on open cliffs in Bay of Plenty; slowly increasing in Northland (Ewen Cameron 1996).
Myoporum insulareAustralian ngaio 1978temp. Australia, Lord Howe Is In Weed Control operational plan for Rangitoto, 1996. Large genetic risk as could hybridise with native species (Cameron, West 1996).
Myrica fayafire tree not yetAzoresHawaiiNaturalised in Chatham Is; not yet seen naturalised mainland NZ, but cultivated widely in NZ. (Lisa Forester & Carol West 1996)
Ottelia ovalifoliaswamp lily 1899Australia Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Fairly aggressive water weed (West 1996)
Pandorea jasminoidesBower vineVine1981Nth NSW, SE Qld Controlled on Little Barrier. Capacity to smother up to mid-canopy. One plant can cover large area with runners. Matting effect in open. Only flowers/fruits in the sun. Fruiting appears rare in NZ.(L Barrier Weed Op. plan 1996). One to watch (West 1996).
Pennisetum purpureumElephant grass, Napier grassGrasspost 1987Trop Afr.GalapagosBTAG trying to ban sale. Growing north of Kaitaia. (Lisa Forester,1996). Repro mainly vegetative. Tolerate range of conditions (0-500 m), but killed by frost. Drought resistant.
Phoenix canariensisCanary Island palm pre 1980Canary Island Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Could be in early lag phase (West 1996). Frequently naturalised near adults; dioecious - should advocate only males are planted (Cameron 1996).
Plectranthus ciliatusplectranthus 1975E and S Africa Worst species of P. ciliatus, ecklonii, grandis group.
Plectranthus eckloniiplectranthusShrub (<3m)1978E and S Africa Mainly spreads vegetatively.
Plectranthus grandisplectranthusShrub (<3m)1988E Africa? Most recent species of P. ciliatus, ecklonii, grandis group.
Podranea ricasolianaPort St John creeper 1981Sth Africa  Aggressive vine; layers (Ewen Cameron 1996)
Pomatogetonclasped pondweedaquaticNot yet. See note  Not yet naturalised. Rhizomes. Hybridises with other species in the genus. Identify by leaf surrounding stem. (Paul Champion, NIWA, 14/8/96)
Pomatogeton crispuscurly pondweed 1940Eurasia, Africa, N. Am, Australia Looks native. Invades submerged aquatic plant communities & replaces native potamogeton & myriophyllum species. (Chris Richmond 1997)
Prunus campanulataTaiwan cherryTree (6-10m)1988East Asia Increasing weed of forest (Cameron 1996).
Prunus laurocerasuscherry laurelTree (<10m)1958SE Europe Poisonous. Expanding range. (Lisa Forester,1996). Sparingly naturalised in Auckland (Cameron 1996). But naturalising in many parts of NZ - need more public awareness of this species (West 1996).
Prunus lusitanicaPortugal laurel 1988Spain, Portugal, Azores (Identified: Lisa Forester, DoC Northland, 14/8/96)
Prunus serrulataJapanese hill cherryTree (>10m)1982China, Japan Growing profusely in catchments where it is established. Widely cultivated. (Lisa Forester, 1996)
Psidium cattleianumpurple guavaShrub (3-5m)1977S BrazilRaoul Is, Hawaii, MauritiusWorth watching (see notes on impacts overseas). Identified for eradication in Raoul Island plan.
Psidium guajavayellow guavaShrub (<3m)1965Trop AmericaRaoul Is, trop. PacificForms solid thickets. Bird dispersed. (Lisa Forester, 1996). Intolerant of frost & deep shade. Waxy cuticle resists herbicides. Possibly too tropical a species to be a major weed on mainland NZ (Cameron 1996). Being eradicated on Raoul Is.
Racosperma melanoxylonTasmanian blackwood 1918E Aust, TasmaniaSth Afr, Argentina, California Invades disturbed forest.
Rhaphiolepsis umbellatasexton's brideShrub (<3m)1982Japan, Korea 6 months flowering, 6 months fruiting. Can invade poor soils so is a species to watch. (Ewen Cameron, 1996)
Rhododendron ponticumrhododendronShrub (3-5m)1958SE Europe, Asia minorUK, IrelandSwamp. wetland, pakahi. Well established West Coast. Dark dense canopy. 12 years before seeding but prolific annual seed. Outbreeder. (Melanie Newfield, 1996).
Ribes sanguineumflowering currantShrub (<3m)1904West N America Spreads readily in Southland (Carol West, 21/8/96)
Robinia pseudacaciafalse acacia 1870C& E Nth AmericaEur, Mediterranean, AustraliaListed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Forest margins.
Rorippa nasturtium-aquaticumwatercress 1852Eurasia, N. Africa Listed as naturalised ecological weeds in Auckland ( Dick Veitch, 1995). Usually in modified streams, but could be desirable to remove from some places (West 1996).
Sagittaria montevidensisarrowhead 1996Nth & Sth America 2m + tall. 100's seeds/flower. Buds off basal rhizome. Sold as pond plant since 1970's. Naturalised in one site. (Paul Champion, NIWA, 14/8/96). Potential major weed.
Schinus terebinthifoliusChristmas berry 1995S AmericaAustralia, Florida, Hawaii, Norfolk Is, MauritiusFirst naturalised Whangaroa 1995, 2nd seedling Mercer 1996. Allelopathic. Dioecious. Invades broad range of habitats, from mangrove to pinelands; esp disturbed habitats. (Ewen Cameron, 1996) Allelopathic. Casts deep shade, excludes understorey.
Spartium junceumSpanish broom 1940Mediterranean In Weed Control operational plan for Rangitoto, 1996.
Stenotaphrum secundatumbuffalo grass 1872trop. America & Africa Listed as naturalised ecological weeds in Auckland (Dick Veitch, 1995). Smothers coastal areas (Cameron 1996).
Tecomaria capensisCape honeysuckle 1958Sth Africa Forms exclusive thickets in full sun and extends into shade, preventing regeneration. Seed is wind dispersed. (Listed in Little Barrier Is. Weed control operational plan, 1996)
Thunbergia grandiflorasky flowerVineNot yet. See note.IndiaAustralia, SingaporeTropical vine. Not yet naturalised in NZ but a big problem in Australia. (Lisa Forester, 1996)
Trachycarpus fortuneiChinese windmill palm    Naturalised freely. ( Ewen Cameron, 1996). Proven to spread & establish mature trees in native forest. Controlled on Little Barrier.
Undaria pinnatifidaseaweedAquatic: marine1987Japan, Korea Brown algae up to 1m+. First discovered Wellington harbour 1987. In 1996 recorded in Timaru, Oamaru, Port Chalmers, Lyttelton, Picton. Mod sheltered to 5 m below low water spring.
Utricularia gibbabladderwortAquatic1980  More wide ranging than native species. Rapidly spreading. Displaces natives. Resistant to sprays & difficult to remove. Forms mats. (Paul Champion, NIWA, 14/8/96)
Number of species: 79


[Hawaiian Ecosystems At Risk]    

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This document was created on 20 July 1999 by PT & CB, and was last updated on 16 April 2005 by LF.