Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Oxalis corniculata
(creeping woodsorrel)

Toolbox

Datasheet

Oxalis corniculata (creeping woodsorrel)

Summary

  • Last modified
  • 08 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Pest
  • Host Plant
  • Preferred Scientific Name
  • Oxalis corniculata
  • Preferred Common Name
  • creeping woodsorrel
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Dicotyledonae
  • Summary of Invasiveness
  • The herbaceous plant O. corniculata is commonly described as being widely naturalized and its origins obscure. The species has many weedy characteristics, being readily self-pollinated, producing copious seed...

Don't need the entire report?

Generate a print friendly version containing only the sections you need.

Generate report

Pictures

Top of page
PictureTitleCaptionCopyright
Oxalis corniculata (creeping woodsorrel); dense ground cover.
TitleInvasive habit
CaptionOxalis corniculata (creeping woodsorrel); dense ground cover.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); dense ground cover.
Invasive habitOxalis corniculata (creeping woodsorrel); dense ground cover.©Trevor James/Hamilton, New Zealand-2014
Habit.
TitleHabit
CaptionHabit.
Copyright©Sheldon Navie
Habit.
HabitHabit.©Sheldon Navie
Oxalis corniculata (creeping woodsorrel); habit in grassland.
TitleHabit in grassland
CaptionOxalis corniculata (creeping woodsorrel); habit in grassland.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); habit in grassland.
Habit in grasslandOxalis corniculata (creeping woodsorrel); habit in grassland.©Trevor James/Hamilton, New Zealand-2014
Young seedling.
TitleSeedling
CaptionYoung seedling.
Copyright©Sheldon Navie
Young seedling.
SeedlingYoung seedling.©Sheldon Navie
Oxalis corniculata (creeping woodsorrel); habit in a lawn.
TitleHabit in a lawn
CaptionOxalis corniculata (creeping woodsorrel); habit in a lawn.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); habit in a lawn.
Habit in a lawnOxalis corniculata (creeping woodsorrel); habit in a lawn.©Trevor James/Hamilton, New Zealand-2014
Young plant.
TitleYoung plant
CaptionYoung plant.
Copyright©Sheldon Navie
Young plant.
Young plantYoung plant.©Sheldon Navie
Oxalis corniculata (creeping woodsorrel); vegetative plant.
TitleVegetative plant
CaptionOxalis corniculata (creeping woodsorrel); vegetative plant.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); vegetative plant.
Vegetative plantOxalis corniculata (creeping woodsorrel); vegetative plant.©Trevor James/Hamilton, New Zealand-2014
Leaves and flowers.
TitleLeaves and flowers
CaptionLeaves and flowers.
Copyright©Sheldon Navie
Leaves and flowers.
Leaves and flowersLeaves and flowers.©Sheldon Navie
Oxalis corniculata (creeping woodsorrel); single flower.
TitleSingle flower
CaptionOxalis corniculata (creeping woodsorrel); single flower.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); single flower.
Single flowerOxalis corniculata (creeping woodsorrel); single flower.©Trevor James/Hamilton, New Zealand-2014
Close-up of flowers.
TitleFlowers
CaptionClose-up of flowers.
Copyright©Sheldon Navie
Close-up of flowers.
FlowersClose-up of flowers.©Sheldon Navie
The flowers are 1-1.5 cm in diameter.
TitleFlowering plant
CaptionThe flowers are 1-1.5 cm in diameter.
Copyright©Chris Parker/Bristol, UK
The flowers are 1-1.5 cm in diameter.
Flowering plantThe flowers are 1-1.5 cm in diameter.©Chris Parker/Bristol, UK
Oxalis corniculata (creeping woodsorrel); fruit capsules.
TitleFruit capsules
CaptionOxalis corniculata (creeping woodsorrel); fruit capsules.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); fruit capsules.
Fruit capsulesOxalis corniculata (creeping woodsorrel); fruit capsules.©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); rooting stolon.
TitleRooting stolon
CaptionOxalis corniculata (creeping woodsorrel); rooting stolon.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); rooting stolon.
Rooting stolonOxalis corniculata (creeping woodsorrel); rooting stolon.©Trevor James/Hamilton, New Zealand-2014
Habit of a single plant.
TitleHabit
CaptionHabit of a single plant.
Copyright©Sheldon Navie
Habit of a single plant.
HabitHabit of a single plant.©Sheldon Navie
Oxalis corniculata (creeping woodsorrel); densely hairy stems of O. corniculate var. villosa.
TitleDensely hairy stems
CaptionOxalis corniculata (creeping woodsorrel); densely hairy stems of O. corniculate var. villosa.
Copyright©Trevor James/Hamilton, New Zealand-2014
Oxalis corniculata (creeping woodsorrel); densely hairy stems of O. corniculate var. villosa.
Densely hairy stemsOxalis corniculata (creeping woodsorrel); densely hairy stems of O. corniculate var. villosa.©Trevor James/Hamilton, New Zealand-2014
Immature fruits.
TitleFruits
CaptionImmature fruits.
Copyright©Sheldon Navie
Immature fruits.
FruitsImmature fruits.©Sheldon Navie

Identity

Top of page

Preferred Scientific Name

  • Oxalis corniculata L.

Preferred Common Name

  • creeping woodsorrel

Other Scientific Names

  • Acetosella corniculata (L.) Kuntz
  • Oxalis langloisii (Small) Fedde
  • Oxalis micrantha BOJ.
  • Oxalis parvifolia
  • Oxalis procumbens A. Rich (1847)
  • Oxalis repens Thunb.
  • Oxlis villosa M. Bieb
  • Xanthoxalis corniculata (L.) Small
  • Xanthoxalis langloisii Small
  • Xanthoxalis repens (Thunb.) Moldenke

International Common Names

  • English: creeping oxalis
  • Spanish: aigret; aleluya amarilla; chulco; hierba de la perdiz; vinagrillo
  • French: oxalis cornicule; surelle jaune
  • Portuguese: erva-azeda-de-folha-pequena

Local Common Names

  • : a 'aa 'a; 'i'i
  • : acedera; acerderilla; agrito; trebol
  • : clover sorrel; creeping lady's sorrel; creeping wood sorrel; creeping woods; creeping yellow oxalis; creeping yellow oxalis; horned oxalis; procumbent yellow sorrel; sheep sorrel; sleeping beauty; sour grass; sour-grass wood-sorrel; wood sorrel; yellow oxalis; yellow wood sorrel
  • : hamd
  • : oseille filante; petit oseille; petit trefle; pied de pigeon; trefle jaune
  • Brazil: azedinha; tres coracoes; tres-coracoes; trevo-azedo
  • China: cu jiang cao
  • Cook Islands: kavakava; koki‘i; koki‘i kura
  • Costa Rica: acederilla; chicha fuerte
  • Fiji: matakonikoni; matakorukoru; rongomi; rongomi; totowiwi
  • French Polynesia: 'ava 'ava; pa 'ihi; pa 'i'l; patoa
  • Germany: Gehoernter Sauerklee; hornfruchtiger Sauerklee; Horn-Sauerklee
  • Italy: carpingna; pancuculo
  • Japan: katabami
  • Micronesia, Federated states of: gougus
  • Netherlands: klaverzuring, gehoornde
  • Northern Mariana Islands: agsom
  • Palau: omis
  • Philippines: daraisig; kanapa; salamagi
  • Sweden: blodaxalis (O. corniculata var. atropurpurea); brunsyra; krypoxalis
  • Tonga: kihikihi
  • USA/Hawaii: ‘ihi maka ‘ula; ‘ihi makole; 'ihi 'ai; 'ihi 'awa

EPPO code

  • OXACO (Oxalis corniculata)
  • OXAMI (Oxalis micrantha)

Summary of Invasiveness

Top of page

The herbaceous plant O. corniculata is commonly described as being widely naturalized and its origins obscure. The species has many weedy characteristics, being readily self-pollinated, producing copious seeds in a short time, and being capable of growing rapidly in open places.

Its spread appears phenomenal. It is considered a cosmopolitan weed of tropical and temperature zones and it probably occurs in most countries in the world, although it may not yet have been reported from all. It occurs in gardens, lawns, arable land and pastures. In Canada it is especially prevalent as a weed of glasshouses. It is a known weed of many crops across the world, from tea in Sri Lanka to rice in Japan.

Its spread has been partly accidental and partly deliberate, since its oxalic acid-containing leaves have long been used for culinary purposes, and for their medicinal and herbal value. 

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Dicotyledonae
  •                     Order: Geraniales
  •                         Family: Oxalidaceae
  •                             Genus: Oxalis
  •                                 Species: Oxalis corniculata

Notes on Taxonomy and Nomenclature

Top of page

As Eiten (1955) said ‘the taxonomy and nomenclature of the caulescent Oxalis related to Oxalis corniculata L. have long been a source of confusion.’ There was difficulty over which herbarium specimen Linnaeus considered the ‘original material’ of the generic name “corniculata”, and three species had been involved in the application of the two Linnean names “O. corniculata” and “O. stricta”. Eiten (1955) separated the original specimens into three species O. corniculata, a creeping, wide-stipuled, pan-tropical species; O. stricta, a tall, cymose, nonstipulate, white-stoloniferous species; and O. dillenii, a hoary, caespitose species native to North America and rare in Europe.

Many subspecies, varieties and forms exist; reflecting the vast genetic variability which can be expected from such a widespread taxa (The Plant List, 2013).   

In the southwestern USA and Mexico, Nesom (2009) presented a key for distinguishing between O. corniculata and the North American native species O. albicans, O. californica, O. dillenii, O. pilosa and O. stricta.

In New Zealand Sykes (2009) described the diagnostic characters used to separate O. corniculata, three similar related adventive species (O. chnoodes, O. dillenii and O. perennans), and three indigenous species (O. exilis, O. rubens and O. thompsoniae). He pointed out that O. corniculata  is very widespread throughout the world and in New Zealand and is a very variable species which overlaps with other species in several characters, especially habit, root system, alignment of stem and petiole hairs, flower position, capsule indumentum and seed ornamentation. Despite this, Sykes considered the species a readily identifiable entity. In Webb et al. (1988) three varieties were named – var. atropurpurea, var. corniculata, var. villosa – although the authors acknowledge that these intraspecific taxa are of doubtful status because there is considerable overlap in characters. They also recognise that the habitats of the three varieties are similar except for var. atropurpurea, which is mostly a garden weed.

Description

Top of page

The following description is adapted from Webb et al. (1988).

O. corniculata is perennial with a slender primary root. Stems are prostrate to suberect, to about 40 cm long, slender, weak, branched, often rooting at nodes, covered with spreading flexible hairs. Leaves with 3 leaflets, alternate, sometimes appearing almost whorled on short lateral stems, green or purple. Petiole (0.5)-1-7 cm long, with spreading flexible hairs; stipules usually 2-3 mm long, broad, with free, truncate apex, nearly glabrous to densely covered in long hairs. Petiolules very short. Lamina of leaflets equal, (2.5)-5-18 × (3)-7-23 mm, broadly obcordate, glabrous or sparsely hairy, with densely hairy midrib below; sinus of lamina narrow or broad, extending 1/2 length of lamina; margin ciliate; calli 0; lobes 2, usually rounded, occasionally leaflets not lobed. Inflorescence 1-5-flowered; peduncle 1-4 cm long, to 9.5 cm long at fruiting, with forward-pointing hairs; pedicels < peduncles, with forward-pointing hairs. Bracts 2-3.2 mm long, linear-subulate or linear-lanceolate, nearly hairless, or hairy at base of pedicels; calli 0. Sepals 3-4.5-(5.2) mm long, elliptic-lanceolate, elliptic-ovate to elliptic-obovate, with forward-pointing hairs; margins sometimes red; calli 0. Petals 4.5-10-(13) mm long, oblong-obovate, yellow, glabrous. Stamens at 2 levels; filaments glabrous, connate towards base. Styles less than, equal to or a little longer than the stamens, densely hairy. Capsule (6)-10-18-(20) mm long, excluding styles, cylindrical, usually densely clothed in short, simple, more or less backward-pointing hairs, or sometimes hairs sparser and then also with scattered, long, wide, curly, septate hairs, occasionally glabrous. Seed 1-1.3-(1.7) cm long, broad-ellipsoid, dark purplish brown; transverse ridges 4-10, either subacute with deep grooves between and sometimes white-topped, or obtuse with shallow grooves.

Plant Type

Top of page Broadleaved
Herbaceous
Perennial
Seed propagated
Vegetatively propagated

Distribution

Top of page

O. corniculata is widespread throughout the world and within many countries. It is considered a cosmopolitan weed of tropical and temperature zones (Holm et al., 1979), and it probably occurs in most countries in the world, although it may not yet have been reported from all.

Holm et al. (1977) describe many crops in many countries where it occurs as a weed – in tea in Sri Lanka, Indonesia and Taiwan; in beans, maize, potatoes, rice and vegetables in Japan; in cereals in Ethiopia; in rice in India and Indonesia; in pastures in Australia; in coffee in El Salvador, India, Kenya, Mexico, Tanzania and Venezuela.

The plant was first reported from near San Francisco by Bolander (1870) and southern California (Brewer et al., 1876), but also had been collected during the 1840s (Howell, 1937). By the late nineteenth century, it had become widely established in southern California (Hilgard, 1890; Robbins, 1940). It has been reported from Santa Cruz and Santa Rosa islands (Junak et al., 1997), and is widespread throughout much of California west of the Sierra Nevada (Ornduff, 1993)’.

O. corniculata has been recorded from the sub-Antarctic islands of Crozet and Kerguelen, but on the latter island only from the vicinity of research stations or habitation (Frenot et al., 2005).

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

AfghanistanPresentHolm et al., 1991; Q-bank, 2013
BhutanPresentParker, 1992; Q-bank, 2013
CambodiaPresentIntroduced Invasive Holm et al., 1977; Holm et al., 1991
ChinaPresentIntroduced Invasive Holm et al., 1977; Holm et al., 1991
-Hong KongWidespread Invasive Holm et al., 1991; Wu Te-lin, 2001Common. In wasteland or along roadside
-ShanghaiPresentHsu, 2010
Christmas Island (Indian Ocean)PresentIntroducedISSG, 2013
Georgia (Republic of)PresentIntroducedKikodze et al., 2010
IndiaPresentIntroduced Invasive Dangwal et al., 2010
-Andhra PradeshPresentIntroduced Invasive Buduru and Satheesh, 2009
-Jammu and KashmirPresentIntroduced Invasive Dangwal et al., 2010
-MaharashtraPresentIntroducedSrinivasu and Pardeshi, 2013
-Uttar PradeshPresentIntroduced Invasive Singh et al., 2010
IndonesiaWidespreadIntroduced Invasive Holm et al., 1977
-SumatraPresentIntroduced Invasive Mangoensoekardjo and Pancho, 1975; Randall, 2012
IranPresentHolm et al., 1991; Q-bank, 2013
IraqPresentHolm et al., 1991; Q-bank, 2013
IsraelPresentIntroduced Invasive Holm et al., 1991; Danin, 2013The Mediterranean woodlands and shrub-land, semi-steppe shru-lands, shrub-steppes, deserts and extreme deserts, Montane vegetation of Mt. Hermon
JapanWidespreadIntroduced Invasive Holm et al., 1977; Holm et al., 1991
Korea, DPRPresentHolm et al., 1991
Korea, Republic ofPresentIntroduced Invasive Holm et al., 1977
MalaysiaPresentIntroduced Invasive Holm et al., 1977; Holm et al., 1991
OmanPresentIntroduced Invasive Saghir, 2003
PakistanWidespreadHolm et al., 1991; eFloras, 2006Common during the spring season from the plains to 2700 m
PhilippinesPresentIntroduced Invasive
Saudi ArabiaPresentAlfarhan et al., 2005
SingaporePresentIntroduced Invasive Waterhouse, 1993; Chong et al., 2009
Sri LankaPresentHolm et al., 1991; Q-bank, 2013
TaiwanPresentIntroduced Invasive Holm et al., 1977; Holm et al., 1991
ThailandPresentIntroduced Invasive Holm et al., 1977; Holm et al., 1991
TurkeyWidespreadIntroduced Invasive Valentine, 1968; Byfield and Baytop, 1998NE Turkey, perhaps elsewhere
VietnamPresentIntroduced Invasive Holm et al., 1977; Holm et al., 1991

Africa

BotswanaPresentSetshogo, 2005
ChadPresentBrundu and Camarda, 2004
Côte d'IvoirePresentQ-bank, 2013
EgyptPresentHolm et al., 1991; Arasi Lawrence Company, 2013
EthiopiaPresentHolm et al., 1991; Firehun and Tamado, 2006
GhanaPresentQ-bank, 2013
GuineaPresentHolm et al., 1991; Q-bank, 2013
KenyaPresentHolm et al., 1991; Q-bank, 2013
LiberiaPresentHolm et al., 1991; Q-bank, 2013
MalawiPresentExell, 1963
MauritiusPresentIntroduced Invasive
MayotteWidespreadIntroduced Invasive Holm et al., 1977; Holm et al., 1991
MoroccoPresentHolm et al., 1991; Q-bank, 2013
MozambiquePresentIntroduced Invasive Holm et al., 1991; Bingham et al., 2013
NamibiaPresentWells et al., 1986; Q-bank, 2013
NigerPresentRanjit & Dhattarai, 1988; Q-bank, 2013
NigeriaPresentHolm et al., 1991; Q-bank, 2013
RéunionPresentIntroduced Invasive Randall, 2012
SeychellesPresentRobertson and Todd, 1983; PIER, 2013
South AfricaPresentIntroduced Invasive Holm et al., 1991; Foxcroft et al., 2003
Spain
-Canary IslandsPresentBrandes and Fritzsch, 2002; Siverio et al., 2011
SwazilandPresentIntroducedWells et al., 1986; Swaziland National Trust Commission, 2013
TanzaniaPresentHolm et al., 1991; Q-bank, 2013
-ZanzibarPresentKabuye, 1971; Q-bank, 2013
UgandaPresentKabuye, 1971; Q-bank, 2013
ZambiaPresentIntroduced Invasive Exell, 1963; Bingham et al., 2013
ZimbabwePresentIntroduced Invasive Holm et al., 1991; Bingham et al., 2013

North America

BermudaPresentIntroducedISSG, 2013
CanadaPresentIntroduced Invasive Doust et al., 1985
-British ColumbiaPresentIntroduced Invasive Doust et al., 1985
-OntarioPresentIntroduced Invasive Doust et al., 1985
-Prince Edward IslandPresentIntroduced Invasive Doust et al., 1985
-QuebecPresentIntroduced Invasive Doust et al., 1985
-SaskatchewanPresentIntroduced Invasive Doust et al., 1985
MexicoPresentHolm et al., 1977
USAPresentHolm et al., 1991
-AlabamaPresentIntroducedUSDA-NRCS, 2013
-ArizonaPresentIntroducedUSDA-NRCS, 2013
-ArkansasPresentIntroducedUSDA-NRCS, 2013
-CaliforniaPresentIntroducedUSDA-NRCS, 2013
-ConnecticutPresentIntroducedUSDA-NRCS, 2013
-DelawarePresentIntroducedUSDA-NRCS, 2013
-District of ColumbiaPresentIntroducedUSDA-NRCS, 2013
-FloridaPresentIntroducedUSDA-NRCS, 2013
-GeorgiaPresentIntroducedUSDA-NRCS, 2013
-HawaiiPresentIntroducedHolm et al., 1991; USDA-NRCS, 2013
-IdahoPresentIntroducedUSDA-NRCS, 2013
-IllinoisPresentIntroducedUSDA-NRCS, 2013
-IndianaPresentIntroducedUSDA-NRCS, 2013
-KentuckyPresentIntroducedUSDA-NRCS, 2013
-LouisianaPresentIntroducedUSDA-NRCS, 2013
-MarylandPresentIntroducedUSDA-NRCS, 2013
-MassachusettsPresentIntroducedUSDA-NRCS, 2013
-MichiganPresentIntroducedUSDA-NRCS, 2013
-MississippiPresentIntroducedUSDA-NRCS, 2013
-MissouriPresentIntroducedUSDA-NRCS, 2013
-MontanaPresentIntroducedUSDA-NRCS, 2013
-NevadaPresentIntroducedUSDA-NRCS, 2013
-New YorkPresentIntroducedUSDA-NRCS, 2013
-OhioPresentIntroducedUSDA-NRCS, 2013
-OklahomaPresentIntroducedUSDA-NRCS, 2013
-OregonPresentIntroducedUSDA-NRCS, 2013
-PennsylvaniaPresentIntroducedUSDA-NRCS, 2013
-Rhode IslandPresentIntroducedUSDA-NRCS, 2013
-South CarolinaPresentIntroducedUSDA-NRCS, 2013
-South DakotaPresentIntroducedUSDA-NRCS, 2013
-TennesseePresentIntroducedUSDA-NRCS, 2013
-TexasPresentIntroducedUSDA-NRCS, 2013
-UtahPresentIntroducedUSDA-NRCS, 2013
-WashingtonPresentIntroducedUSDA-NRCS, 2013
-WisconsinPresentIntroducedUSDA-NRCS, 2013
-WyomingPresentIntroducedUSDA-NRCS, 2013

Central America and Caribbean

AnguillaPresentIntroducedISSG, 2013
Cayman IslandsPresentIntroducedISSG, 2013
Costa RicaPresentHolm et al., 1979; Holm et al., 1991
CubaPresentAcuna, 1974; Holm et al., 1991
El SalvadorWidespreadHolm et al., 1991
GuadeloupePresentFournet, 1993
GuatemalaPresentHolm et al., 1979
JamaicaPresentQ-bank, 2013
Netherlands AntillesFournet and Hammerton, 1991
Puerto RicoPresentHolm et al., 1991; Liogier, 2000
Trinidad and TobagoPresentQ-bank, 2013

South America

ArgentinaWidespreadCARDENAS and COULSTON, 1967; Holm et al., 1991
BoliviaPresentWells et al., 1986; Q-bank, 2013
BrazilWidespreadCARDENAS and COULSTON, 1967; Holm et al., 1991
-Rio Grande do SulPresentSchneider, 2007
ChilePresentHolm et al., 1991
ColombiaWidespreadHolm et al., 1991
French GuianaPresentFunk et al., 2007
GuyanaPresentFunk et al., 2007
ParaguayPresentRandall, 2012
PeruPresentHolm et al., 1991
SurinamePresentFunk et al., 2007
VenezuelaPresentHolm et al., 1991; Q-bank, 2013

Europe

AlbaniaPresentValentine, 1968; Q-bank, 2013
AustriaPresentEssl and Rabitsch, 2002
BelgiumPresent, few occurrencesIntroducedHYPPA, 2013
BulgariaPresentValentine, 1968; Q-bank, 2013
CroatiaPresentIntroducedNikolic, 2006; Q-bank, 2013
Czechoslovakia (former)PresentPysek et al., 2002
DenmarkPresentIntroducedRandall, 2012
FinlandPresentIntroducedRandall, 2012
FrancePresentQ-bank, 2013
-CorsicaPresentValentine, 1968; Q-bank, 2013
GermanyPresent, few occurrencesIntroducedLinares, 2000
GibraltarPresentLinares, 2000
GreecePresentValentine, 1968; Q-bank, 2013
HungaryPresentBotond and Zoltan, 2004
IcelandPresentDAISIE, 2008
IrelandPresentIntroducedMilbau and Stout, 2006
ItalyPresentIntroduced Invasive Holm et al., 1991; HYPPA, 2013
LithuaniaPresentDAISIE, 2008
LuxembourgPresentDAISIE, 2008
MaltaPresentIntroducedFournet and Hammerton, 1991
NetherlandsPresentValentine, 1968; DAISIE, 2008
NorwayPresentValentine, 1968; DAISIE, 2008
PolandPresentIntroduced1863 Not invasive Valentine, 1968; Institute and Polish, 2012Earliest introduction/record in 1863
PortugalPresentValentine, 1968; Q-bank, 2013
-AzoresPresentIntroducedValentine, 1968; DAISIE, 2013
RomaniaPresentIntroducedValentine, 1968; DAISIE, 2008
Russian FederationPresentHolm et al., 1991; Q-bank, 2013
SerbiaPresentNestorovic and Konstantinovic, 2011
SlovakiaPresentIntroducedDAISIE, 2008
SloveniaPresentIntroducedDAISIE, 2008
SpainPresentPeralta and Royuela, 2013
-Balearic IslandsPresentValentine, 1968; Q-bank, 2013
SwedenPresentValentine, 1968; Q-bank, 2013
SwitzerlandPresentValentine, 1968; Q-bank, 2013
UKWidespreadIntroduced Invasive Biological Records Centre, 2013Cultivated in Britain by 1656 and first recorded in the wild in 1770
Yugoslavia (former)PresentValentine, 1968; Q-bank, 2013

Oceania

American SamoaPresentIntroduced Invasive Whistler, 1990; Waterhouse, 1997; PIER, 2013
AustraliaPresentHolm et al., 1979; Holm et al., 1991
-Australian Northern TerritoryPresent Invasive Richardson et al., 2006
-New South WalesPresent Invasive Richardson et al., 2006
-QueenslandPresent Invasive Richardson et al., 2006
-South AustraliaPresent Invasive Richardson et al., 2006
-TasmaniaPresent Invasive Richardson et al., 2006
-VictoriaPresent Invasive Richardson et al., 2006
-Western AustraliaPresent Invasive Richardson et al., 2006
Cook IslandsPresentIntroduced Invasive Waterhouse, 1997; McCormack, 2013Introduced - Polynesia; Land, lowlands - inland valleys
FijiPresentSmith, 1985; Holm et al., 1991
French PolynesiaPresentIntroduced Invasive Waterhouse, 1997; Smithsonian Museum of Natural History, 2012Cosmopolitan species of unknown origin. In the Marquesas, naturalised on Nuku Hiva, Ua Huka, Ua Pou, Hiva Oa, tahuata, Fatu Hiva
GuamPresentStone, 1970; Waterhouse, 1997
KiribatiPresentIntroducedISSG, 2013
Marshall IslandsEradicatedIntroducedVander Velde, 2003Recent introduction. Rare, possibly extirpated. Weed at Japanese Take-out Restaurant, observed in 1991 but not seen again
Micronesia, Federated states ofPresent Invasive Wagner et al., 2012
NauruPresent, few occurrencesIntroducedThaman et al., 1994Pre-World War I introduction: reported by Schumann and Lauterbach (1901) as collected by Finsch. Rare, weed at MQ 40 Command Ridge
New CaledoniaPresentNativeSwarbrick, 1997
New ZealandPresentWebb et al., 1988; Holm et al., 1991
NiuePresentIntroduced Invasive Space et al., 2004
Norfolk IslandPresentNativeOrchard, 1994Usually found in disturbed ground
Northern Mariana IslandsPresent Invasive Fosberg et al., 1975In disturbed areas. Maug. Northern end of East Island, below 400 ft (120 m). Sarigan: Above village, 250-300 ft (75-90 m)
PalauPresentNativeWagner et al., 2012
Papua New GuineaPresentHenty & Pritchard, 1995; Peekel, 1984
Pitcairn IslandPresentIntroducedFosberg et al., 1989
SamoaPresentIntroducedPIER, 2013Aboriginal introduction
Solomon IslandsPresentNativeHancock and Henderson, 1988; Swarbrick, 1997
TongaPresentWaterhouse, 1997; PIER, 2013
VanuatuPresentSwarbrick, 1997; Waterhouse, 1997
Wallis and Futuna IslandsPresentWaterhouse, 1997Vegetables, lawns

History of Introduction and Spread

Top of page

Eiten (1963) postulated that O. corniculata originated in the New World but debated whether it evolved as a new species there or evolved first in the Old World and then spread to the New World. His conclusion was that it probably originated in the southeastern portion of the Old World and then migrated, most likely over a warmer Greater Antarctica, to the southern part of South America and from there it moved northwards, with new species diverging in different locations and times.

Its spread has been partly accidental and partly deliberate, since its oxalic acid-containing leaves have long been used for culinary purposes, and are also of medicinal or herbal value (PFAF, 2013).

The plant is still spreading in some countries. The Online Atlas of the British and Irish flora, (2013) reports that it was cultivated in Britain by 1656 and was first recorded in the wild in 1770, but its main spread was in the 1900s and this has continued. It has consolidated its range in the south, and is now more widely recorded in northern Britain and Ireland.

Wilken and Hannah (1998) note ‘that it was first reported from near San Francisco by Bolander (1870) and southern California (Brewer et al., 1876), but also had been collected during the 1840s (Howell, 1937). By the late 1800s, it had become widely established in southern California (Hilgard, 1890; Robbins, 1940).’

Introductions

Top of page
Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Australia 1856 Yes CHAH (2014); Council of Heads of Australasian Herbaria (2013)
New Zealand 1944 Yes Webb et al. (1988) Possibly introduced earlier - early taxonomy confused
UK 1656 Horticulture (pathway cause) Yes Biological Records Centre (2013) Cultivated in Britain by 1656; first recorded in the wild in 1770
USA 1840s Yes Howell (1937) By late 19th century widely established in southern California

Risk of Introduction

Top of page

The risk of introduction to new countries appears slight, since it is already present in many countries or may be present but as yet unrecorded in others. However, it can still spread further within the countries in which it is already established. 

Habitat

Top of page

O. corniculata is a common weed of gardens, lawns, arable land and pastures (GISD, 2013) in both tropical and temperate regions throughout the world (PIER, 2013). In parts of the Northern Hemisphere, it is remarkable for its ability to invade and spread in greenhouses (Lovett Doust et al., 1985; Holt, 1987).  

In Hawaii it occurs ‘in open, disturbed sites in coastal to subalpine habitats, 0-2,399 m’ (Wagner et al., 1999; PIER, 2013), and in Fiji ‘at elevations from near sea level to about 750 m as a common weedy plant along roads and trails in moist places, pastures, waste places, plantations and in villages’ (Smith, 1985; PIER, 2013). In New Guinea it is found from near sea level to at least 2800 m, a plant of ‘grassland, broken forest, rock faces, and a weed of gardens, roadsides and waste land (Henty and Pritchard, 1975; PIER, 2013), and in Tonga it is ‘a common plantation and waste-area weed (Yuncker, 1959; PIER, 2013). 

Habitat List

Top of page
CategoryHabitatPresenceStatus
Terrestrial-managed
Cultivated / agricultural land Principal habitat
Disturbed areas Present, no further details
Protected agriculture (e.g. glasshouse production) Principal habitat
Rail / roadsides Present, no further details
Terrestrial-natural/semi-natural
Natural forests Present, no further details
Natural grasslands Present, no further details
Riverbanks Present, no further details

Hosts/Species Affected

Top of page

Holm et al. (1977) give a list of the crops and countries in which O. corniculata occurs as a weed. However, there is little information on whether the species interferes with crop growth, since it is a very low-growing and relatively inconspicuous weed. The species is also common in glasshouses and in lawns in some countries but again, its presence may be a cosmetic rather than a yield-limiting problem, although controlling it could involve considerable expense.  

Host Plants and Other Plants Affected

Top of page
Plant nameFamilyContext
Ananas comosus (pineapple)BromeliaceaeOther
Arachis hypogaea (groundnut)FabaceaeOther
Camellia sinensis (tea)TheaceaeMain
CitrusRutaceaeMain
Coffea (coffee)RubiaceaeMain
Manihot esculenta (cassava)EuphorbiaceaeOther
Musa (banana)MusaceaeOther
Oryza sativa (rice)PoaceaeMain
pasturesOther
Phaseolus (beans)FabaceaeOther
PyrethrumAsteraceaeOther
Saccharum officinarum (sugarcane)PoaceaeOther
Solanum tuberosum (potato)SolanaceaeOther
turfgrassesOther
Zea mays (maize)PoaceaeMain

Biology and Ecology

Top of page

Genetics

Many chromosome numbers have been recorded, including 2n=18, 20, 22 and 20-24 (Eiten, 1959; Lovett Doust et al., 1985).

Reproductive Biology

O. corniculata shows morphological traces of a tristylous breeding system (Ornduff, 1972), resulting from its adaptation to a weedy niche, which favoured the evolution of increased inbreeding and the breakdown of trimorphic incompatability (Ornduff, 1972; Lovett Doust et al., 1981).  Lovett Doust et al. (1981) found that plants of this species showed equally high seed set whether the corolla was removed or not; highest seed set occurred when flowers were left to self-pollinate. In this and some related species, the two whorls of stamens are distinct but the midlength styles and the longer whorl of stamens are more or less of equal length, making the flowers ‘semihomostylous mids’, in the terminology of Ornduff (1972).

As described by Robertson (1975) dehiscence of the capsules occurs through the loculicidal split on the abaxial side of each capsule. At maturity the slits open slightly, the abaxial carpel walls thin and flap-like. The seeds are enclosed in a smooth turgid aril which splits suddenly along an abaxial suture and turns inside out. This action ejects the seed and often the aril through the slit to a considerable distance from the parent plant (up to 2 m) (Lovett Doust et al., 1985). The ejection of one seed sets off a chain reaction that results in the dispersal of most seeds in one capsule in a very short time. The seeds of O. corniculata are sticky and adhere to objects on which they land.

Resvani et al. (2010) tested the distribution of seeds from varieties of O. corniculata – var. atropurpurea and var. parvifolia – in pots in a plastic glasshouse with little wind. For both taxa, most seeds fell close to the source, with a minor secondary mode at 1-1.5m. In most cases pods are held beneath the leaf canopy so as more seeds collide with vegetation and drop to the ground. The authors also found that there was a statistically significant relationship between dispersal distance and seed mass, where heavier seeds travel further.

By contrast Holt (1987), working with glasshouse grown plants in California, observed that a single mature plant could disperse over 800 seeds in 24 hours to a distance of 5m. There were a constant number of seeds per pod (48) and the total weight of seeds per pod was 9mg.

It is commonly found as a problem weed in greenhouses in North America and there it can grow and reproduce all year round. Holt (1986) investigated the effect of environmental factors on the germination and dormancy of greenhouse-produced seeds. Seeds were germinated at 17 ± 2oC, which was found to be the optimum temperature for germination. Freshly produced seeds required only very low levels of light for germination: after four weeks at only 0.25% full sunlight (5 μmol m-2 s-1), 100% of seeds had germinated. However germination was faster in higher light levels. In complete darkness, though, no germination took place after four weeks. Regardless of season of production, freshly-matured seeds showed less than 10% dormancy and germinated over a broad range of temperatures. Seeds produced in winter had the narrowest temperature range of germination (15-20oC) and those produced in summer the widest temperature range (10-30oC). Seeds stored dry at room temperature showed no significant reduction in germinability for 8 months after collection, but after 15 months germination capacity was reduced to about 50%.

Physiology and Phenology

Although the main apex of O. corniculata is determinate, seldom exceeding 15 cm in length, lateral shoots borne on stolons are indeterminate in growth and continue to produce flowers as they grow (Lovett Doust et al., 1985). Interestingly, in tropical Fiji Smith (1985) describes stems as ‘rarely exceeding 50 cm’ and plants as ‘comparatively large, with prostrate or repent stems up to 50 cm long’, which suggests that main stems or lateral shoots or both may be longer in warmer climates. 

Seal and Sen (1975) found that O. corniculata fixed 14C into oxalic acid within both light and dark conditions, but the rate was greater in the light. In light conditions 14C could be detected in oxalic acid within 5 seconds of exposure to the gas.

In warmer environments (in greenhouses, warmer parts of countries or in warmer countries), the plants are perennials, but in cooler environments (outdoors in Canada or the United Kingdom) they behave as annuals, overwintering as seeds (Lovett Doust et al., 1985; Webb et al., 1988; Stace, 2010).

Holt (1987) found that O. corniculata seeds stored under laboratory conditions for one year retained nearly 75% of their original germination capacity. Although in warmer climes clonal growth could presumably allow plants to survive for many years, there appears to be no information on this.

Zhang et al. (2001) assessed the seed banks in the soil of abandoned farmland previously used for crops like sweet potato and peanuts, in the north of Guangdong Province, China, and found that O. corniculata  was the second most common species, with 1357 seeds m-2 in the top 10 cm of the soil. The existing vegetation on the site was described as ‘native weeds and some seedlings of an introduced woody species’, so O. corniculata may have been among them.

In Canada most outdoor populations of O. corniculata are re-established each spring from seed and even in British Columbia where the species can overwinter outdoors, most of the plants found early in the growing season were seedlings (Lovett Doust et al., 1985).  In California, Holt (1986) found that in glasshouses in California the plants completed one life cycle in five weeks from seed to seed. For this reason, many generations of the weed are possible within a year under glasshouse conditions.

Associations

O. corniculata is commonly found as a weed of lawns, crops, pastures and glasshouses and thus is found in association with many other plant species, including many crops, grass and clover species and other weedy species. It has also been recorded with fungal associations, for example Lovett Doust et al. (1985) list a number of maize sorghum and Andropogon rusts for which O. corniculata can serve as an alternate host.

Environmental Requirements

O. corniculata occurs in open, disturbed places and does not perform well in shade (PFAF, 2013; PIER, 2013), although Holm et al. (1977) reports that it is also found in shady areas. It occurs in a very wide range of environments from the tropics (Fiji, Hawaii, New Guinea, etc.) to cooler climates such as Canada and Scandinavia. Most Canadian specimens examined by Lovett Doust et al. (1985) came from greenhouses or the warmer southwest Ontario or British Columbia. These authors suggested that cold winter conditions restrict the distribution of O. corniculata further north in Canada. 

PFAF (2013) indicates that O. corniculata is equally at home in light, medium or heavy soils with acid, neutral or basic pH, but that it prefers dry sites. Apart from that account there appears to be little information on the edaphic requirements of the species. However its extremely wide distribution suggests that perhaps it is very catholic in its requirements. Wada et al. (2004), however, found that O. corniculata germinated poorly with virtually no growth and lowering in alkaline substrates of pH greater than 7, achieved by the addition of high rates of pulverized dolomitic limestone to soil in containers.

Natural enemies

Top of page
Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Oidium oxalidis Pathogen
Puccinia bakshii Pathogen Leaves
Tetranychina harti Herbivore Leaves
Ustilago oxadalis Pathogen

Means of Movement and Dispersal

Top of page

The plants themselves do not spread far by stolons or rhizomes, but seed of O. corniculata have evidently been carried long distances by human agency, either deliberately or accidentally.

Natural Dispersal

O. corniculata has stolons which can root at the nodes and thus spread the plant clonally. These rooted nodes (ramets) may regenerate after burning, weeding or rototilling (Lovett Doust et al., 1985; Gardener and Marrinan, 2013). Seeds naturally disperse considerable distances (up to 2 m) from the parent plant during dehiscence of the capsule (Robertson, 1975; Lovett Doust et al., 1985).

Vector Transmission

Lovett Doust et al. (1985) suggest that seeds may be spread further by rodents, as is the case with the larger-seeded O. acetosella. The occurrence of O. corniculata on remote islands also suggests that the seeds may be carried by birds (Holm et al., 1979).

Accidental Introduction

Since O. corniculata is so widespread and common its accidental introduction to new countries or to new locations within countries is easily achieved. This is likely to be through contamination of agricultural machinery or seed, or by transfer of seeds on footwear, clothing, vehicle wheels, etc.

Intentional Introduction

O. corniculata has long been recognised as a valuable condiment and also for its medical or herbal properties: this has almost certainly been one of the reasons for its wide spread throughout most of the world, a spread that could easily continue.

Pathway Causes

Top of page
CauseNotesLong DistanceLocalReferences
Garden waste disposal Yes
Horticulture Yes Yes
Nursery trade Yes Yes
Ornamental purposes Yes Yes
People sharing resources Yes Yes

Pathway Vectors

Top of page
VectorNotesLong DistanceLocalReferences
Clothing, footwear and possessions Yes
Machinery and equipment Yes

Impact Summary

Top of page
CategoryImpact
Economic/livelihood Negative
Environment (generally) Negative
Human health Positive

Economic Impact

Top of page

O. corniculata is found in many crops in many different countries, but there appears to be no information on how much effect this weedy species has on crop yield or quality.  The species can also act as an alternate host to maize rusts, sorghum rust and Andropogon rust so its presence could provide a source of infection (Lovett Doust et al., 1985).

As this species can be difficult to control in both gardens and greenhouses considerable expense can be incurred in attempts to eliminate it.

O. corniculata is considered poisonous to livestock in some circumstances. Herbiguide (2013) states that most reports result from hungry sheep being exposed to dense stands, and that pregnant ewes seem to be the most sensitive class of stock, followed by lambs, then wethers, then cattle. Oxalate crystals may form in the kidneys, resulting in permanent damage. Animals accustomed to the plant do not usually suffer any ill-effects. The symptoms of poisoning are muscular trembling or rigidity or both, staggering, heavy breathing, loss of control of the hindquarters and collapsing onto the ground, and slimy discharge from the nostrils. Death occurs a few hours to six weeks after consumption. 

Environmental Impact

Top of page

Although reported as a weed of lawns, glasshouses and many crops in a number of countries, there are few reports of any environmental effects of O. corniculata on habitat or biodiversity.

Social Impact

Top of page

PFAF (2013) recommends that ‘people with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition.’

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Has a broad native range
  • Abundant in its native range
  • Highly adaptable to different environments
  • Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
  • Pioneering in disturbed areas
  • Benefits from human association (i.e. it is a human commensal)
  • Fast growing
  • Has high reproductive potential
  • Has propagules that can remain viable for more than one year
  • Reproduces asexually
  • Has high genetic variability
Impact mechanisms
  • Competition - monopolizing resources
  • Poisoning
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Highly likely to be transported internationally deliberately
  • Difficult to identify/detect as a commodity contaminant
  • Difficult to identify/detect in the field
  • Difficult/costly to control

Uses

Top of page

Economic Value

The leaves of O. corniculata can be used raw or cooked, added to salads, cooked as a potherb with other, milder flavoured greens or used to give a sour flavour to other foods (PFAF, 2013).

The following medicinal uses are described by PFAF (2013):

‘The whole plant is anthelmintic, antiphlogistic, astringent, depurative, diuretic, emmenagogue, febrifuge, lithontripic, stomachic and styptic. It is used in the treatment of influenza, fever, urinary tract infections, enteritis, diarrhoea, traumatic injuries, sprains and poisonous snake bites. The juice of the plant, mixed with butter, is applied to muscular swellings, boils and pimples. An infusion can be used as a wash to rid children of hookworms. The plant is a good source of vitamin C and is used as an antiscorbutic in the treatment of scurvy. The leaves are used as an antidote to poisoning by the seeds of Datura spp, arsenic and mercury. The leaf juice is applied to insect bites, burns and skin eruptions. It has an antibacterial activity.’

A number of scientific studies on the chemical constitution of O. corniculata seem to support the medicinal claims made for this species. Kumar et al. (2012) reviewed the literature on the subject and concluded that the herb should be studied more extensively for its therapeutic benefits. Das et al. (2012) tested the possible heptaprotective activity of extracts on rats and found that they seemed to show dose dependent reduction of necrosis induced by thioacetamide.

Social Benefit

O. corniculata has many uses in traditional culinary and herbal practices in many countries. 

Uses List

Top of page

Environmental

  • Host of pest

General

  • Sociocultural value

Human food and beverage

  • Spices and culinary herbs

Medicinal, pharmaceutical

  • Traditional/folklore

Ornamental

  • Propagation material

Similarities to Other Species/Conditions

Top of page

O. corniculata itself is very variable in form and its wide geographic distribution and its long journey, if Eiten’s (1963) idea is true, from Australasia to South America and then far beyond, resulted in this species spawning other species along the way, many of which have characteristics in common with their possible parent species. This would help explain the confusion which has arisen in many countries over the taxonomy of species, especially in the Corniculatae group of Oxalis (Young, 1958; Eiten, 1963; Watson, 1989; Nesom, 2009; Sykes, 2009).

The trifoliate leaves of O. corniculata can cause confusion with species of clover (Trifolium spp.), especially the small-leaved Trifolium dubium, but clovers have pea-shaped flowers. O. corniculata can also be easily confused with other species of Oxalis that have small leaves and flowers. For example the New Zealand native O. exilis is similar in many respects to O. corniculata, but usually has smaller leaves and its flowers are solitary instead of in clusters of 2-5 flowers (Sykes, 2009). The North American species O. stricta (or O. dillenii) and O. europaea, which are widely naturalized in Europe, also have similar foliage and flowers to O. corniculata but somewhat more erect stems and do not root at the nodes.

In the southwestern USA and Mexico, Nesom (2009) presented a key for distinguishing between O. corniculata and the North American native species O. albicans , O. californica , O. dillenii, O. pilosa and O. stricta.

In New Zealand Sykes (2009) described the diagnostic characters used to separate O. corniculata, three similar related adventive species (O. chnoodes, O. dillenii and O. perennans), and three indigenous species (O. exilis, O. rubens and O. thompsoniae). He pointed out that O. corniculata  is very widespread throughout the world and in New Zealand and is a very variable species which overlaps with other species in several characters, especially habit, root system, alignment of stem and petiole hairs, flower position, capsule indumentum and seed ornamentation. Despite this, Sykes considered the species a readily identifiable entity. In Webb et al. (1988) three varieties were named – var. atropurpurea, var. corniculata, var. villosa – although the authors acknowledge that these intraspecific taxa are of doubtful status because there is considerable overlap in characters. They also recognise that the habitats of the three varieties are similar except for var. atropurpurea, which is mostly a garden weed.

Prevention and Control

Top of page

Physical/Mechanical Control

Herbiguide (2013) suggests mowing (and grazing) is generally ineffective and manual removal is difficult. UC-IPM Online (2013) proposes that it can be controlled through hand-weeding and hand cultivation with hoes and weeding tools, but recommends following such treatments up with post-emergent herbicides. It also advises burying seeds or covering them with mulch to block their exposure to light so as to prevent germination. Fertilising or irrigating is also not effective: ‘the more vigorous the turfgrass, the more vigorous the creeping woodsorrel’ (UC-IPM Online, 2013).

Movement Control

To prevent further spread of the weed, a lawn mower that has been used where creeping woodsorrel grows, should be washed or airsprayed to remove all seeds and clippings before mowing weed-free turf. Furthermore, considerable caution should be taken when purchasing container plants from nurseries to ensure that the weed is not moved to new greenhouses or gardens (UC-IPM Online, 2013).

Biological Control

No biological control has been suggested for O. corniculata.

Chemical Control

The two areas in which chemical control of O. corniculata seems to be of most interest are in turf grasses and in container plants, the latter especially in the United States. In turfgrass the herbicides most commonly used for selective control, like MCPA, 2,4-D, dicamba, and mecoprop, are relatively ineffective (Lovett Doust et al., 1985; Holt, 1986; Kaapro, 2002). In cool-season turf grass (Agrostis spp., Lolium spp., Poa pratensis or Schedonorusarundinaceus) triclopyr or fluroxypyr is recommended by UC-IPM Online (2013) to control seedling and established O. corniculata, along with some other herbicides. In warm season grasses (Buchloe dactyloides, Cenchrus clandestinus, Cynodon dactylon, Stenotaphrum secundatum and Zoysia spp.), UC-IPM Online (2013) suggests fluroxypyr as a post-emergence herbicide for controlling O. corniculata. Triclopyr is harmful to Cynodon dactylon and Cenchrus clandestinus.

UC-IPM Online (2013) suggests a number of herbicides to be used around landscape plantings, but recommends considerable caution.

Holt (1988) found the growth regulator NAA showed promise as a herbicide for O. corniculata control in some ornamentals. Colvin and Rice (1987) found triclopyr gave good control of the weed in Cymbidium orchids.

Control by Utilization

Grazing is generally found to be ineffective as the plant is too low growing and intricately entwined with other species to be readily accessible to grazing animals (Herbiguide, 2013). 

Gaps in Knowledge/Research Needs

Top of page

Despite the almost universal distribution of O. corniculata, there is little information regarding its growth patterns, longevity, physiology or impact on either agricultural practices or the environment. 

References

Top of page

Acuna GJ, 1974. Plantas indeseables en los cultivos Cubanos:240 pp.

Alfarhan AH; Al-Turki TA; Basahy AY, 2005. Weeds of Jizan Province. AR-17-7 - Final Report, Vol.- 1. Supported by King Abdulaziz City for Science and Technology (KACST), 1:545 pp.

Arasi Lawrence Company, 2013. Weeds of Egypt. Arasi Lawrence Company. http://www.arasi.freeservers.com/weedslist/weedso.htm

Bingham MG; Willemen A; Wursten BT; Ballings P; Hyde MA, 2013. Flora of Zambia., Zambia: Flora of Zambia. http://www.zambiaflora.com/index.php

Biological Records Centre, 2013. Online Atlas of the British and Irish flora. Wallingford, UK: Biological Records Centre. http://www.brc.ac.uk/plantatlas/

Bolander H, 1870. A catalog of plants growing in the vicinity of San Francisco. San Francisco, California, USA: A. Roman and Co, 43 pp.

Botond M; Zoltan BD, 2004. Biological invasions in Hungary. Invasive Plants. TermészetBÚVÁR Alapítvány Kiadó.

Brandes D; Fritzsch K, 2002. Alien plants of Fuerteventura, Canary Islands (Plantas extranjeras de Fuerteventura, Islas Canarias). Arbeitsgruppe fur Vegetationsokologie und experimentelle Pflanzensoziologie Botanisches Institut und Botanischer Garten der TU Braunschweig. http://opus.tubs.de/opus/volltexte/2000/79/pdf/alien.pdf

Brewer W; Watson S; Gray A, 1876. Geological Survey of California. Volume 1, 1. Cambridge, Massachusetts, USA: John Wilson, University Press, 622 pp.

Brundu G; Camarda I, 2004. The exotic flora of Chad: a first contribution. Weed Technology [Invasive plants in natural and managed systems (IPINAMS) conference, Fort Lauderdale, Florida, USA, November 2003.], 18(Suppl.):1226-1231.

Buduru Salomeyesudas; Satheesh PV, 2009. Traditional food system of Dalit in Zaheerabad Region, Medak District, Andhra Pradesh, India. In: Indigenous peoples' food systems: the many dimensions of culture, diversity and environment for nutrition and health [ed. by Kuhnlein, H. V.\Erasmus, B.\Spigelski, D.]. Rome, Italy: Food and Agriculture Organization of the United Nations (FAO), 185-208.

Bugbee GJ; Balfour ME, 2010. Rorippa microphylla. Connecticut's Invasive and wetland plants: identification guide:37 pp. http://ct.gov/caes/lib/caes/invasive_aquatic_plant_program/pdf_reports/b1027.pdf

Byfield AJ; Baytop A, 1998. Three alien species new to the flora of Turkey. Turkish Journal of Botany, 22(3):205-208.

CARDENAS J; COULSTON L, 1967. 400] Weeds of Argentina. A list of common and scientific names. Mimeograph. Oregon St. Univ. Agency int. Dev, 67-12:17 pp.

CARDENAS J; COULSTON L, 1967. 400] Weeds of Brazil. A list of common and scientific names. Mimeograph. Oregon St. Univ. Agency int. Dev, 67-13:14 pp.

Chong KY; Tan HTW; Corlett RT, 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Singapore: Raffles Museum of Biodiversity Research, National University of Singapore, 273 pp. http://lkcnhm.nus.edu.sg/nus/pdf/PUBLICATION/LKCNH%20Museum%20Books/LKCNHM%20Books/flora_of_singapore_tc.pdf

Chopra RN; Nayar SL; Chopra IC, 1956. Glossary of Indian medicinal plants. Glossary of Indian medicinal plants. New Delhi: Council of Scientific and Industrial Research, unpaginated.

Colvin S; Rice Jr RP, 1987. Selective post-emergence control of Oxalis corniculata in Cymbidium hybrida. Journal of environmental horticulture, 5(3):141-142.

Council of Heads of Australasian Herbaria, 2013. Australia's virtual herbarium. Australia: Council of Heads of Australasian Herbaria. http://avh.ala.org.au

DAISIE, 2008. European Invasive Alien Species Gateway. www.europe-aliens.org

DAISIE, 2013. Delivering Alien Invasive Species Inventories for Europe. DAISIE (online). www.europe-aliens.org

Dangwal LR; Amandeep Singh; Tajinder Singh; Antima Sharma; Chanchal Sharma, 2010. Common weeds of rabi (winter) crops of Tehsil Nowshera, District Rajouri (Jammu & Kashmir), India. Pakistan Journal of Weed Science Research, 16(1):39-45. http://www.wssp.org.pk/

Danin A, 2013. Flora of Israel online. Jerusalem, Israel: The Hebrew University of Jerusalem. http://flora.huji.ac.il/browse.asp

Doust LL; Doust JL; Cavers PB, 1981. Fertility relationships in closely related taxa of Oxalis, section Corniculatae. Canadian Journal of Botany, 59(12):2603-2609.

Doust LL; MacKinnon A; Doust JL, 1985. Biology of Canadian weeds. 71. Oxalis stricta L., O. corniculata L., O. dillenii Jacq. ssp. dillenii and O. dillenii Jacq. ssp. filipes (Small) Eiten. Canadian Journal of Plant Science, 65(3):691-709.

Duke JA; Ayensu ES, 1985. Medicinal Plants of China. 2 Vols. Algonac, Michigan, USA: Reference Publ., Inc, 705 pp.

eFloras, 2006. Flora of Pakistan. Missouri, USA: Missouri Botanical Garden.

eFloras, 2012. Flora of Pakistan. Missouri, USA: Missouri Botanical Garden. http://www.efloras.org

Eiten G, 1955. The typification of the names "Oxalis corniculata L." and "Oxalis stricta L.". Taxon, 4(5):99-105.

Eiten G, 1959. PhD thesis. New York, USA: Columbia University.

Eiten G, 1963. Taxonomy and regional variation of Oxalis section Corniculatae. introduction, keys and synopsis of the species. American Midland Naturalist, 69(2):257-309.

Essl F; Rabitsch W, 2002. Neobiota in Osterreich (Alien species in Austria). Vienna, Austria: Umweltbundesamt GmbH.

Exell AW, 1963. 38. Oxalidaceae. In: Exell AW, Fernandez A, Wild H, eds. Flora Zambesiaca, Volume 2, Part 1. London, UK: Crown Agents, 149-162.

Exell AW, 1963. Oxalidaceae: Oxalis corniculata L. Flora Zambesiaca. Kew, UK: Kew Royal Botanic Gardens. http://apps.kew.org/efloras/namedetail.do?flora=fz&taxon=1183&nameid=2879

Facciola S, 1998. Cornucopia - a source book of edible plants. Vista, California: Kampong Publications, 713 pp.

Firehun Y; Tamado T, 2006. Weed flora in the Rift Valley sugarcane plantations of Ethiopia as influenced by soil types and agronomic practises. Weed Biology and Management, 6:139-150.

Fosberg FR; Falanruw MVC; Sachet M-H, 1975. Vascular flora of the Northern Marianas Islands [: an annotated list in systematic order]. Smithsonian Contributions to Botany, No. 22. iii, 45 pp.

Fosberg FR; Paulay G; Spencer T; Oliver R, 1989. New collections and notes on the plants of Henderson, Pitcairn, Oeno, and Ducie Islands. Atoll Research Bulletin, 329:18 pp.

Fournet J, 1993. Phytoecological characteristics of weed populations in sugar cane and banana plantations in Basse Terre (Guadeloupe). (Caractérisation phytoécologique des peuplements de mauvaises herbes des champs de canne à sucre et des bananeraies de la Basse Terre (Guadeloupe).) Weed Research (Oxford), 33(5):383-395.

Fournet J; Hammerton JL, 1991. Weeds of the Lesser Antilles. Techniques and Practises. Paris, France: INRA Editions, CARDI, 214 pp.

Foxcroft LC; Henderson L; Nichols GR; Martin BW, 2003. A revised list of alien plants for the Kruger National Park. Koedoe, 46(2):21-44.

Frenot Y; Chown SL; Whinam J; Selkirk P; Convey P; Skotnicki M; Bergstrom D, 2005. Biological invasions in the Antarctic: extent, impacts and implications. Biological Reviews, 80:45-72.

Funk V; Hollowell T; Berry P; Kelloff C; Alexander SN, 2007. Checklist of the plants of the Guiana Shield (Venezuela: Amazonas, Bolivar, Delta Amacuro; Guyana, Surinam, French Guiana). Contributions from the United States National Herbarium, 584 pp.

Gardener M; Marrinan M, 2013. Fire responses of Oxalis corniculata. Tropical Savannas Fire Response Database. Darwin, Australia: Northern Land Manager. http://www.landmanager.org.au/fire-responses-oxalis-corniculata

Hancock IR; Henderson CP, 1988. Flora of the Solomon Islands. Research Bulletin No. 7, 7. Honiara, Soloman Islands: Ministry of Agriculture and Lands, 203 pp.

Henty EE; Pritchard GH, 1975. Weeds of New Guinea and their Control. Lp, Papua New Guinea: Department of Forests, Division of Botany, Botany Bulletin No.7.

Herbiguide, 2013. Herbiguide. http://www.herbiguide.com.au/

Hilgard E, 1890. The weeds of California. California Agricultural Experiment Station Report. 238-252 pp.

Holm LG; Pancho JV; Herberger JP; Plucknett DL, 1979. A geographical atlas of world weeds. New York, USA: John Wiley and Sons, 391 pp.

Holm LG; Pancho JV; Herberger JP; Plucknett DL, 1991. A Geographic Atlas of World Weeds. Malabar, Florida, USA: Krieger Publishing Company.

Holm LG; Plucknett DL; Pancho JV; Herberger JP, 1977. The World's Worst Weeds. Distribution and Biology. Honolulu, Hawaii, USA: University Press of Hawaii.

Holt JS, 1986. Control of creeping woodsorrel in ornamentals. Newsletter. California, USA: EJ Slosson Endowment for Ornamental Horticulture, University of California, Agriculture and Natural Resources, 30-31 pp. http://slosson.ucdavis.edu/newsletters/Holt_198629146.pdf

Holt JS, 1987. Factors affecting germination in greenhouse-produced seeds of Oxalis corniculata, a perennial weed. American Journal of Botany, 74(3):429-436.

Holt JS; Chism WJ, 1988. Herbicidal activity of NAA (1-Naphthaleneacetic acid) on creeping woodsorrel (Oxalis corniculata) in ornamentals. Weed Science, 36(2):227-233.

Howell J, 1937. A Russian collection of California plants. Leaflets of Western Botany, 2:17-20.

Hsu PS, 2010. The exotic flora of Shanghai: A comparison with Hongkong and Singapore. Shanghai Science and Technology Museum, 2(4):1-24.

HYPPA, 2013. Unité de Malherbologie & Agronomie. HYPPA.

Institute of Nature Conservation Polish Academy of Sciences, 2013. Alien Species in Poland. Kraków, Poland: Institute of Nature Conservation, Polish Academy of Sciences. http://www.iop.krakow.pl/ias/Baza.aspx

Institute of Nature Conservation; Polish Academy of Sciences, 2012. Alien Species in Poland. Kraków, Poland. Institute of Nature Conservation, Polish Academy of Sciences. http://www.iop.krakow.pl/ias/Baza.aspx

ISSG, 2013. Global Invasive Species Database (GISD). Auckland, New Zealand: University of Auckland. http://www.issg.org/database

ITIS, 2013. Integrated Taxonomic Information System (ITIS). Washington, DC, USA: Smithsonian Institution/NMNH. http://www.itis.gov/

John EFogarty International Center for Advanced Study in the Health Sciences, 1974. A barefoot doctor's manual: Oxalis corniculata L. Maryland, USA: John E. Fogarty International Center for Advanced Study in the Health Sciences, National Institute of Health, 960 pp. http://www.scribd.com/doc/38130410/A-Barefoot-Doctors-Manual-1974

Junak S; Chaney S; Philbrick R; Clark R, 1997. A Checklist of Vascular Plants of Channel Islands National Park. Tucson, AZ, USA: Southwest Parks and Monuments Association.

Kaapro J, 2002. Control of Oxalis corniculata in turf. In: 13th Australian Weeds Conference: weeds "threats now and forever?", Sheraton Perth Hotel, Perth, Western Australia, 8-13 September 2002: papers and proceedings [ed. by Jacob, H. S.\Dodd, J.\Moore, J. H.]. Victoria Park, Australia: Plant Protection Society of Western Australia Inc, 225-226.

Kabuye CHS, 1971. Oxalidaceae. In: Milne-Redhead E, Polhill RM, eds. Flora of Tropical East Africa. London, UK: Crown Agents.

Kikodze D; Memiadze N; Kharazishvili D; Manvelidze Z; Mueller-Schaerer, 2010. The alien flora of Georgia. Second Edition. Swiss National Science Foundation, Swiss Agency for Development and Cooperation and SCOPES, 40 pp. http://www.unifr.ch/biol/ecology/muellerschaerer/group/mueller/webpage/pdf/research/Invasives_GE.pdf

Kumar A; Rani NS; Sagwai S, 2012. An absolute review on Oxalis corniculata Linn. International Journal of Research in Pharmaceutical and Biomedical Sciences, 3(3):1173-1188.

Kuntal Das; Kathiriya AK; Kumar EP; Benson MK; Einstein JW, 2012. Evaluation of hepatoprotective activity of aqueous and ethanolic extract of Oxalis corniculata against intoxication of thioacetamide induced rats. Revista Brasileira de Farmacognosia, 22(2):412-417. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-695X2012000200023&lng=en&nrm=iso&tlng=en

Linares L, 2000. Checklist of the Gibraltar Flora., Gibraltar: Gibraltar Ornithological and Natural History Society. http://www.gonhs.org/flora.htm

Liogier HA, 2000. Flora of Puerto Rico and adjacent Islands. A systematic synopsis, edition 2, Puerto Rico: Universidad de Puerto Rico.

Manandhar NP, 2002. Plants and people of Nepal [ed. by Manandhar, N. P.]. Portland, USA: Timber Press, 599 pp.

Mangoensoekardjo S; Pancho JV, 1975. Current Status of weed problems in plantation crops. Bulletin B.P.P.M, 6(1).

McCormack G, 2013. Cook Islands Biodiversity Database, Version 2007. Cook Islands Biodiversity Database. Rarotonga, Cook Islands: Cook Islands Natural Heritage Trust. http://cookislands.bishopmuseum.org/search.asp

Milbau A; Stout JC, 2006. Database of alien plants in Ireland. Dublin, Ireland: School of Natural Sciences, Trinity College Dublin.

Nesom GL, 2009. Notes on Oxalis sect. Corniculatae (Oxalidaceae) in the southwestern United States. Phytologia, 91(3):527-533.

Nestorovic MLJ; Konstantinovic B, 2011. Overview of the weed flora in the Serbia. Savremena Poljoprivreda, Srpski casopis za poljoprivredne nauke. [Contemporary Agriculture,The Serbian Journal of Agricultural Sciences], 60(1-2):215-230.

Nikolic T, 2006. Flora Croatica. (Flora Croatica baza podataka.) Flora Croatica Database [ed. by Nikolic, T.]. http://hirc.botanic.hr/fcd

Nikolic T, 2013. Flora Croatica (Flora Croatica baza podataka). Flora Croatica Database.

Orchard AE, 1994. Flora of Australia. Vol. 49, Oceanic islands 1. Canberra, Australia: Australian Government Publishing Service.

Ornduff R, 1972. The breakdown of trimorphic incompatibility in Oxalis section Corniculatae. Evolution, 26:52-85.

Ornduff R, 1993. Oxalidaceae. In: The Jepson manual: Vascular plants of California [ed. by Hickman, J.]. Berkeley, USA: University of California Press, 808-809 pp.

Parker C, 1992. Weeds of Bhutan. Weeds of Bhutan., vi + 236 pp.

Peekel PG, 1984. Flora of the Bismarck Archipelago for naturalists. Lae, Papua New Guinea: Office of Forests, Division of Botany, 638 pp.

Peralta J; Royuela M, 2013. Flora arvense of Navarra (Flora arvense of Navarra). Navarra, Spain: Departamento de Ciencias del Medio Natural Universidad Publica de Navarra. http://www.unavarra.es/servicio/herbario/htm/concepto.htm

PFAF, 2013. Database. Plants for a Future. http://www.pfaf.org/user/plantsearch.aspx

PIER, 2013. Pacific Islands Ecosystems at Risk. Honolulu, Hawaii, USA: HEAR, University of Hawaii. http://www.hear.org/pier/index.html

Pysek P; Sádlo J; Mandák B, 2002. Catalogue of alien plants of the Czech Republic. Preslia, 74(2):97-186.

Q-bank, 2013. Comprehensive databases of quarantine plant pests and diseases. Q-bank. http://www.q-bank.eu/Plants/BioloMICS.aspx?Table=Plants%20-%20Species&Rec=75&Fields=All

Randall RP, 2012. A Global Compendium of Weeds. Perth, Australia: Department of Agriculture and Food Western Australia, 1124 pp. http://www.cabi.org/isc/FullTextPDF/2013/20133109119.pdf

Ranjit JD; Bhattarai AN, 1988. Crop Weeds and their Control in Nepal. Kathmandu, Nepal: Winrock International/USAID.

Rezvani M; Cousens RD; Zaefarian F; Karimmojeni H; Robinson AP, 2010. Shapes of ballistic seed dispersal distributions: a comparison of Oxalis corniculata with a theoretical model. Weed Research (Oxford), 50(6):631-637. http://www.blackwell-synergy.com/loi/wre

Richardson FJ; Richardson RG; Shepherd RCH, 2006. Weeds of the South-East. Meredith, Victoria, Australia: R.G. and F.J. Richardson, 438 pp.

Robbins W, 1940. .

Robbins W, 1940. Alien plants growing without cultivation in California. Berkeley, California, USA: University of California, 128 pp. [Agricultural Experiment Station Bulletin 637.]

Robertson KR, 1975. Th Oxlidaceae in the southeastern United States. Journal of the Arnold Arboretum, 56:223-239.

Robertson SA; Todd DM, 1983. Vegetation of Fregate Island, Seychelles. Floristics and ecology of Western Indian Ocean islands. Atoll Research Bulletin No. 273:253 pp.

Saghir AR, 2003. Important weed species in crops and countries, western Asia, Oman. Data stored from 59 developing countries and regularly updated. FAO Weed Management Database. FAO Weed Management Database.

Schneider AA, 2007. The naturalised flora of Rio Grande Do Sul State, Brazil: Subspontaneous Herbaceous Plants, 15(2). Porto Alegre, Brazil: BIOCIENCIAS, 257-268 pp.

Seal SN; Sen SP, 1970. The photosynthetic production of oxalic acid in Oxalis corniculata. Plant Cell Physiology, 11:119-128.

Setshogo MP, 2005. Preliminary Checklist of the Plants of Botswana, Southern African Botanical Diversity Network, Report No. 37, 37. Pretoria and Gaborone, South Africa: SABONET, 161 pp.

Singh KP; Shukla AN; Singh JS, 2010. State-level inventory of invasive alien plants, their source regions and use potential. Current Science, 99(1):107-114. http://www.ias.ac.in/currsci

Siverio A; Sobrino E; Rodríguez H; Arévalo JR, 2011. Weeds of golf courses on the island of Tenerife. (Malas hierbas de los campos de golf de la isla de Tenerife.) In: Plantas invasoras resistencias a herbicidas y detección de malas hierbas. XIII Congreso de la Sociedad Española de Malherbología, La Laguna, Spain, 22-24 November 2011 [ed. by Arévalo JR, Fernández S, López F, Recasens J, Sobrino E]. Madrid, Spain: Sociedad Española de Malherbología (Spanish Weed Science Society), 83-86.

Smith AC, 1985. Flora Vitensis: a new flora of Fiji, 3. Hawaii, USA: National Tropical Botanical Garden, 758 pp.

Smithsonian Museum of Natural History, 2012. Smithsonian Museum of Natural History Botany Collections. Botany Collections. Washington, DC, USA: Smithsonian Museum of Natural History. http://collections.mnh.si.edu/search/botany/?qt=Sacciolepis+indica

Space JC; Waterhouse BM; Newfield M; Bull C, 2004. Report to the Government of Niue and the United Nations Development Programme: Invasive plant species on Niue following Cyclone Heta. 80 pp. [UNDP NIU/98/G31 - Niue Enabling Activity.] http://www.hear.org/pier/reports/niue_report_2004.htm

Srinivasu T; Pardeshi S, 2013. Floristic survey of the Institute of Science campus, Mumbai, Maharashtra State. Mumbai, India: Department of Botany, Institute of Science, Mumbai.

Stace CA, 2010. New flora of the British Isles. 3rd edition. Cambridge, UK: Cambridge University Press, 1232 pp.

Stone BC, 1970. The flora of Guam. Micronesia, 6:1-659.

Stuart GA, 1911. Chinese materia medica. San Francisco, USA: Georgetown Press.

Swarbrick JT, 1997. Weeds of the Pacific Islands. Technical paper No. 209. Noumea, New Caledonia: South Pacific Commission.

Swaziland National Trust Commission, 2013. Swaziland's alien plants database. Lobamba, Swaziland: Swaziland National Trust Commission. http://www.sntc.org.sz/alienplants/

Sykes WR, 2009. The Oxalis corniculata group. New Zealand Journal of Botany, 47:107-113.

Tanaka T, 1976. Tanaka's Cyclopedia of edible plants of the world. Tokyo, Japan: Keigaku Pub. Co, 924 pp.

Thaman RR; Fosberg FR; Manner HI; Hassall DC, 1994. The flora of Nauru. Atoll Research Bulletin, 392:1-223.

The Plant List, 2013. The Plant List: a working list of all plant species. Version 1.1. London, UK: Royal Botanic Gardens, Kew. http://www.theplantlist.org

UC-IPM, 2012. Statewide Integrated Pest Management Program. California, USA: University of California.

UC-IPM, 2013. Creeping woodsorrel and Bermuda buttercup. How to manage pests: pests in gardens and landscapes. California, USA: University of California Agriculture and Natural Resources: Statewide Integrated Pest Management Program. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7444.html

USDA-NRCS, 2013. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http://plants.usda.gov/

Usher G, 1974. A dictionary of plants used by man. A dictionary of plants used by man. Constable and Company Ltd. London UK, 619pp.

Valentine DH, 1968. LXXXII. Oxalidaceae. In: Tutin TG, Heywood VH, Burges NA, Moore DM, Valentine DH, Walters SM, Webb DA, eds. Flora Europaea, Volume 2. Rosaceae to Umbelliferae. Cambridge, UK: Cambridge University Press, 192-193.

Vander Velde N, 2003. The vascular plants of Majuro Atoll, Republic of the Marshall Islands. Washington DC, USA: National Museum of Natural History, Smithsonian Institution, 141 pp.

Wada S; Altland J; Mallory-Smith C; Stang J; Holownia G, 2004. Weed Control, Proceedings of the Southern Nursery Association Research Conference [ed. by Neal (ed), J. C.]. http://www.sna.org/Resources/Documents/04resprocsec08.pdf

Wagner WL; Herbst DR; Sohmer SH, 1999. Manual of the flowering plants of Hawaii. Revised edition. Honolulu, Hawaii, USA: University of Hawaii Press/Bishop Museum Press, 1919 pp.

Wagner WL; Herbst DR; Tornabene MW; Weitzman A; Lorence DH, 2012. Flora of Micronesia website. Washington DC, USA: Smithsonian Institution. http://botany.si.edu/pacificislandbiodiversity/micronesia/index.htm

Waterhouse DF, 1993. The Major Arthropod Pests and Weeds of Agriculture in Southeast Asia. ACIAR Monograph No. 21. Canberra, Australia: Australian Centre for International Agricultural Research, 141 pp.

Waterhouse DF, 1997. The major invertebrate pests and weeds of agriculture and plantation forestry in the southern and western Pacific. Canberra, Australia: Australian Centre for International Agricultural Research. 93 pp. [ACIAR Monograph No. 44].

Webb CJ; Sykes WR; Garnock-Jones PJ, 1988. Flora of New Zealand. Vol. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. Christchurch, New Zealand: Botany Division, D.S.I.R, 1365 pp.

Wells MJ; Balsinhas AA; Joffe H; Engelbrecht VM; Harding G; Stirton CH, 1986. A catalogue of problem plants in South Africa. Memoirs of the botanical survey of South Africa No 53. Pretoria, South Africa: Botanical Research Institute.

Whistler WA, 1988. Checklist of the weed flora of Western Polynesia. An annotated list of the weed species of Samoa, Tonga, Niue, and Wallis and Futuna, along with the earliest dates of collection and the local names. Technical Paper, South Pacific Commission, No. 194:69 pp.

Whistler WA, 1990. The weeds of Manu'a [unpublished checklist]. 18.

Wilken D; Hannah L, 1998. Oxalis corniculata (Oxalidaceae): Creeping Wood-Sorrel. California, USA: Santa Barbara Botanic Garden and Channel Islands National Park. www.npwrc.usgs.gov/resource/literatr/aprs/lit/oxalis%20corniculatus.doc

Wu Te-lin, 2001. Check list of Hong Kong plants. Hong Kong Herbarium and the South China Institute of Botany. Agriculture, Fisheries and Conservation Department Bulletin 1 (revised):384 pp. http://www.hkherbarium.net/herbarium/PDF/Eng%20part%202_Dicots.pdf

YOUNG DP, 1958. Oxalis in the British Isles. Watsonia, 4(2):51-71.

Yuncker TG, 1959. Plants of Tonga. Bishop Museum Bulletin 220.

Zhang ZQ; Shu WS; Lan CY; Wong MH, 2001. Soil seed banks as an input of seed source in revegetation of lead/zinc mine tailings. Restoration Ecology, 9(4):378-385.

Contributors

Top of page

01/10/13 Original text by:

Ian Popay, consultant, New Zealand, with the support of Landcare Research

Distribution Maps

Top of page
You can pan and zoom the map
Save map