Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Portulaca oleracea
(purslane)

Toolbox

Datasheet

Portulaca oleracea (purslane)

Pictures

Top of page
PictureTitleCaptionCopyright
Portulaca oleracea (purslane); shoot, with blooms.
TitleShoot with blooms
CaptionPortulaca oleracea (purslane); shoot, with blooms.
Copyright©Didier Descouens - CC BY-SA 3.0
Portulaca oleracea (purslane); shoot, with blooms.
Shoot with bloomsPortulaca oleracea (purslane); shoot, with blooms.©Didier Descouens - CC BY-SA 3.0
Portulaca oleracea (purslane); from a typical, open, disturbed habitat purslane grows rapidly, producing flowers, fruits and seeds within 6 weeks of germination.
TitlePropagation
CaptionPortulaca oleracea (purslane); from a typical, open, disturbed habitat purslane grows rapidly, producing flowers, fruits and seeds within 6 weeks of germination.
Copyright©S.D. Sawant
Portulaca oleracea (purslane); from a typical, open, disturbed habitat purslane grows rapidly, producing flowers, fruits and seeds within 6 weeks of germination.
PropagationPortulaca oleracea (purslane); from a typical, open, disturbed habitat purslane grows rapidly, producing flowers, fruits and seeds within 6 weeks of germination.©S.D. Sawant
Portulaca oleracea (purslane); 1, Granulate pattern; 2, stellate (S-undulate) pattern in P. oleracea.
TitleSeed patterns
CaptionPortulaca oleracea (purslane); 1, Granulate pattern; 2, stellate (S-undulate) pattern in P. oleracea.
Copyright©J.F. Matthews
Portulaca oleracea (purslane); 1, Granulate pattern; 2, stellate (S-undulate) pattern in P. oleracea.
Seed patternsPortulaca oleracea (purslane); 1, Granulate pattern; 2, stellate (S-undulate) pattern in P. oleracea.©J.F. Matthews
Portulaca oleracea (purslane); 3, Stellate (S-undulate) tuberculate pattern; 4, raised stellate (S-undulate) pattern without tubercles, in P. oleracea.
TitleSeed patterns
CaptionPortulaca oleracea (purslane); 3, Stellate (S-undulate) tuberculate pattern; 4, raised stellate (S-undulate) pattern without tubercles, in P. oleracea.
Copyright©J.F. Matthews
Portulaca oleracea (purslane); 3, Stellate (S-undulate) tuberculate pattern; 4, raised stellate (S-undulate) pattern without tubercles, in P. oleracea.
Seed patternsPortulaca oleracea (purslane); 3, Stellate (S-undulate) tuberculate pattern; 4, raised stellate (S-undulate) pattern without tubercles, in P. oleracea.©J.F. Matthews
Portulaca oleracea (purslane); 5, Raised stellate (S-undulate) pattern with incipient tubercles; 6, granulate pattern with tubercles of  P. oleracea.
TitleSeed patterns
CaptionPortulaca oleracea (purslane); 5, Raised stellate (S-undulate) pattern with incipient tubercles; 6, granulate pattern with tubercles of P. oleracea.
Copyright©J.F. Matthews
Portulaca oleracea (purslane); 5, Raised stellate (S-undulate) pattern with incipient tubercles; 6, granulate pattern with tubercles of  P. oleracea.
Seed patternsPortulaca oleracea (purslane); 5, Raised stellate (S-undulate) pattern with incipient tubercles; 6, granulate pattern with tubercles of P. oleracea. ©J.F. Matthews
Portulaca oleracea (purslane); 7, Raised stellate (S-undulate) pattern with definite tubercles; 8, root- tip squash showing 2n=26 in P. oleracea.
TitleSeed and root tip
CaptionPortulaca oleracea (purslane); 7, Raised stellate (S-undulate) pattern with definite tubercles; 8, root- tip squash showing 2n=26 in P. oleracea.
Copyright©J.F. Matthews
Portulaca oleracea (purslane); 7, Raised stellate (S-undulate) pattern with definite tubercles; 8, root- tip squash showing 2n=26 in P. oleracea.
Seed and root tipPortulaca oleracea (purslane); 7, Raised stellate (S-undulate) pattern with definite tubercles; 8, root- tip squash showing 2n=26 in P. oleracea.©J.F. Matthews
Portulaca oleracea (purslane); general habit, showing foliage and flowers.
TitleHabit
CaptionPortulaca oleracea (purslane); general habit, showing foliage and flowers.
Copyright©A.R. Pittaway
Portulaca oleracea (purslane); general habit, showing foliage and flowers.
HabitPortulaca oleracea (purslane); general habit, showing foliage and flowers.©A.R. Pittaway
Close-up of foliage and flower; close-up of foliage and flowers.
TitleFoliage and flowers
CaptionClose-up of foliage and flower; close-up of foliage and flowers.
Copyright©A.R. Pittaway
Close-up of foliage and flower; close-up of foliage and flowers.
Foliage and flowersClose-up of foliage and flower; close-up of foliage and flowers.©A.R. Pittaway
Portulaca oleracea (purslane); flowering habit.
TitleHabit
CaptionPortulaca oleracea (purslane); flowering habit.
Copyright©Chris Parker/Bristol, UK
Portulaca oleracea (purslane); flowering habit.
HabitPortulaca oleracea (purslane); flowering habit.©Chris Parker/Bristol, UK

Identity

Top of page

Preferred Scientific Name

  • Portulaca oleracea Linnaeus 1753

Preferred Common Name

  • purslane

Other Scientific Names

  • Portulaca diptera Zippelius ex. Spanoghe
  • Portulaca fosbergii Poelln.
  • Portulaca marginata HBK
  • Portulaca neglecta MacKenzie & Bush
  • Portulaca parviflora Haw.
  • Portulaca retusa Engelmann
  • Portulaca sativa Haw.

International Common Names

  • English: duckweed; garden purslane; little-hogweed; pursley; pusley; pussley; wild portulaca
  • Spanish: verdolaga
  • French: courpier; pourcellaine; pourpie potager; pourpier
  • Portuguese: beldroega-comum

Local Common Names

  • China: ma chi xian; ma chia xian
  • Germany: Portulak, Gelber
  • Italy: erba porcellana; porcellana; porcellana comune
  • Japan: Suberi-hiyu
  • Netherlands: postelein, wilde
  • Sweden: portulak, vanlig

EPPO code

  • POROL (Portulaca oleracea)

Taxonomic Tree

Top of page
  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Dicotyledonae
  •                     Order: Caryophyllales
  •                         Family: Portulacaceae
  •                             Genus: Portulaca
  •                                 Species: Portulaca oleracea

Notes on Taxonomy and Nomenclature

Top of page Portulaca oleracea (purslane) is an ancient, cosmopolitan species in which self fertilization is the rule. Hence, local populations exist which reflect variable morphological and physiological traits expressed as part of the genome of that population. However, purslane has not been split into a series of microspecies.

The two most recent comprehensive monographs, Legrand (1962) and Geesink (1969) provide, respectively, only three and two names as synonyms. Gorske et al. (1979) conducted a numerical taxonomic analysis of 36 morphological characters on 44 ecotypes from 18 countries, which included the cultivated form commonly known as Portulaca oleracea var. sativa. They found three morphological groups, that form a clime: (1) cool temperate, (2) warm temperate to subtropic and (3) humid subtropic to tropic. They did not propose that these groups should receive nomenclatural recognition.

Danin et al. (1978) proposed nine subspecies, on the basis of seed size, seed surface pattern and chromosome number. However, it may be that these subspecies could be expanded almost ad infinitum on the basis of the variety of seed surface patterns that can be found in the species (Matthews et al., 1993). Legrand (1962) stated that seed size, sepal wings and number of stamens are environmentally influenced and that seed surface pattern was not predictable or dependable as a taxonomic character because of the infinite transition patterns that are present.

In a chemotaxonomic study comparing proteins and free amino acids, Prabhakar and Ramayya (1988) found that, within the complex P. oleracea, the var. ophemera is distinct from vars oleracea and sativa.

Matthews et al. (1993) concluded that P. oleracea exists as a polymorphic species and is not readily divisible into subspecies on the basis of seed surface patterns, chromosome number or other morphological traits that are subject to environmental influences.

Description

Top of page P. oleracea is mostly an annual, but it may be perennial in the tropics. Stems are glabrous, fleshy, purplish-red to green, arising from a taproot, often prostrate, forming mats. The leaves (also fleshy) are alternate, subalternate or opposite, obovate to spatulate with an obtuse or truncate-emarginate apex. The leaves may range from 40 mm x 15 mm up to 60 mm x 25 mm in fertile soils. Apical whorls have 2-5 leaves, usually 4. Axillary hairs are missing, inconspicuous or barely visible. Flowers are in a group at the end of the stem. The 2 sepals are fused at the base of the ovary and may form a wing-like carina 3-4 mm long that can cover the fruit. There are (4)5(6) yellow petals ranging from 3 to 10 mm long by 2 to 8 mm wide with 6-15 (3-20) stamens. The style branches are 3-6, the capsule ranges from 4 to 9 mm, opening at or just below the middle. Seeds are black when mature, but may be red or brown when immature. The seeds are 0.6-1 mm long, usually with granulate to flat-stellate surfaces. However, other patterns, with raised stellate and tuberculate surfaces can occur.

Plant Type

Top of page Annual
Biennial
Broadleaved
Herbaceous
Seed propagated
Succulent
Vegetatively propagated

Distribution

Top of page P. oleracea grows from sea level to 2600 m (Vengris et al., 1972) and is most common in the temperate and subtropical regions, although it extends into the tropics and higher latitudes. Common latitudes are between 45°N and 40°S, with extension to 58°N in North America and 54°N in Europe (Matthews et al., 1993).

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

AfghanistanPresentKitamura, 1960
BangladeshPresentHolm et al., 1991
CambodiaPresentWaterhouse, 1993
ChinaPresentHolm et al., 1991
-Hong KongPresentYip, 1976
IndiaPresentHolm et al., 1991
-Andhra PradeshPresentPrabhakar et al., 1990
-ChandigarhPresentKhullar and Dutta, 1973
-Madhya PradeshPresentShukla, 1971
-RajasthanPresentBhandari, 1978
-Uttar PradeshPresentSingh, 1973
IndonesiaPresentWaterhouse, 1993
-JavaPresentBacker & van der Brink, 1963
-KalimantanPresentHolm et al., 1991
IranPresentHolm et al., 1991
IraqPresentHolm et al., 1991
IsraelPresentNovoplansky, 1991
JapanPresentPresent based on regional distribution.
-HokkaidoPresentOhwi, 1965
-HonshuPresentOhwi, 1965
-KyushuPresentOhwi, 1965
-ShikokuPresentOhwi, 1965
JordanPresentHolm et al., 1991
Korea, Republic ofPresentKim, 1993
LebanonPresentPost, 1932
MalaysiaPresentWaterhouse, 1993
MyanmarPresentWaterhouse, 1993
NepalPresentHara et al., 1978
PakistanPresentStewart, 1972
PhilippinesPresentMerrill, 1912; Poncho, 1986
Saudi ArabiaPresentChaudhary et al., 1981
SingaporePresentWaterhouse, 1993
Sri LankaPresentGunawardena, 1968
SyriaPresentPost, 1932
TaiwanPresentLi, 1975-79; Li, 1979
ThailandPresentGeesink, 1975
TurkeyPresentWalters, 1964
VietnamPresentJeanplong, 1973

Africa

AlgeriaPresentQuezel and Santa, 1962
AngolaPresentHolm et al., 1991
BurundiPresentvon Poellnitz, 1934
CongoPresentvon Poellnitz, 1934
Congo Democratic RepublicPresentHolm et al., 1991
Côte d'IvoirePresentHutchinson and Dalziel, 1954
EgyptPresentTõckholm, 1956
EthiopiaPresentBlundell, 1992
GhanaPresentHutchinson and Dalziel, 1954
GuineaPresentHutchinson and Dalziel, 1954
KenyaPresentBlundell, 1992
LesothoPresentGuillarmod, 1971
LiberiaPresentHutchinson and Dalziel, 1954
LibyaPresentMouterde, 1966
MaliPresentHutchinson and Dalziel, 1954
MauritiusPresentBaker, 1877
MoroccoPresentHolm et al., 1991
MozambiquePresentBlundell, 1992
NigerPresentHooker, 1849
NigeriaPresentHutchinson and Dalziel, 1954
RwandaPresentvon Poellnitz, 1934
SenegalPresentHutchinson and Dalziel, 1954
SeychellesPresentBaker, 1877
Sierra LeonePresentHutchinson and Dalziel, 1954
SomaliaPresentBlundell, 1992
South AfricaPresentHolm et al., 1991
Spain
-Canary IslandsPresentSiverio et al., 2011
SudanPresentBroun and Massey, 1929
TanzaniaPresentBlundell, 1992
UgandaPresentBlundell, 1992
ZambiaPresentHolm et al., 1991
ZimbabwePresentHolm et al., 1991

North America

BermudaPresentIntroducedBritton, 1918
CanadaPresentPresent based on regional distribution.
-AlbertaPresentIntroducedMiyanishi and Cavers, 1980
-British ColumbiaPresentIntroducedMiyanishi and Cavers, 1980
-ManitobaPresentIntroducedMiyanashi & Cavers, 1980
-New BrunswickPresentIntroducedMiyanishi and Cavers, 1980
-Northwest TerritoriesPresentIntroducedMiyanishi and Cavers, 1980
-Nova ScotiaPresentIntroducedMiyanishi and Cavers, 1980
-OntarioPresentIntroducedMiyanishi and Cavers, 1980
-Prince Edward IslandPresentIntroducedMiyanishi and Cavers, 1980
-QuebecPresentIntroducedMiyanishi and Cavers, 1980
-SaskatchewanPresentIntroducedMiyanishi and Cavers, 1980
-Yukon TerritoryPresentIntroducedMiyanishi and Cavers, 1980
MexicoPresentIntroducedRzendowski and Rzendowski, 1979
USAPresentPresent based on regional distribution.
-AlabamaPresentIntroducedZimmerman, 1976
-AlaskaPresentIntroducedZimmerman, 1976
-ArizonaPresentIntroducedZimmerman, 1976
-ArkansasPresentIntroducedZimmerman, 1976
-CaliforniaPresentIntroducedZimmerman, 1976
-ColoradoPresentIntroducedZimmerman, 1976
-ConnecticutPresentIntroducedZimmerman, 1976
-DelawarePresentIntroducedZimmerman, 1976
-FloridaPresentIntroducedZimmerman, 1976
-GeorgiaPresentIntroducedZimmerman, 1976
-HawaiiPresentIntroducedZimmerman, 1976
-IdahoPresentIntroducedZimmerman, 1976
-IllinoisPresentIntroducedZimmerman, 1976
-IndianaPresentIntroducedZimmerman, 1976
-IowaPresentIntroducedZimmerman, 1976
-KansasPresentIntroducedZimmerman, 1976
-KentuckyPresentIntroducedZimmerman, 1976
-LouisianaPresentIntroducedZimmerman, 1976
-MainePresentIntroducedZimmerman, 1976
-MarylandPresentIntroducedZimmerman, 1976
-MassachusettsPresentIntroducedZimmerman, 1976
-MichiganPresentIntroducedZimmerman, 1976
-MinnesotaPresentIntroducedZimmerman, 1976
-MississippiPresentIntroducedZimmerman, 1976
-MissouriPresentIntroducedZimmerman, 1976
-MontanaPresentIntroducedZimmerman, 1976
-NebraskaPresentIntroducedZimmerman, 1976
-NevadaPresentIntroducedZimmerman, 1976
-New HampshirePresentIntroducedZimmerman, 1976
-New JerseyPresentIntroducedZimmerman, 1976
-New MexicoPresentIntroducedZimmerman, 1976
-New YorkPresentIntroducedZimmerman, 1976
-North CarolinaPresentIntroducedZimmerman, 1976
-North DakotaPresentIntroducedZimmerman, 1976
-OhioPresentIntroducedZimmerman, 1976
-OklahomaPresentIntroducedZimmerman, 1976
-OregonPresentIntroducedZimmerman, 1976
-PennsylvaniaPresentIntroducedZimmerman, 1976
-Rhode IslandPresentIntroducedZimmerman, 1976
-South CarolinaPresentIntroducedZimmerman, 1976
-South DakotaPresentIntroducedZimmerman, 1976
-TennesseePresentIntroducedZimmerman, 1976
-TexasPresentIntroducedZimmerman, 1976
-UtahPresentIntroducedZimmerman, 1976
-VermontPresentIntroducedZimmerman, 1976
-VirginiaPresentIntroducedZimmerman, 1976
-WashingtonPresentIntroducedZimmerman, 1976
-West VirginiaPresentIntroducedZimmerman, 1976
-WisconsinPresentIntroducedZimmerman, 1976
-WyomingPresentIntroducedZimmerman, 1976

Central America and Caribbean

AnguillaPresentIntroducedHoward, 1988
BahamasPresentIntroducedCorrell, 1982
BarbadosPresentIntroducedGooding et al., 1965
British Virgin IslandsPresentIntroducedHoward, 1988
Costa RicaPresentIntroducedBurger, 1971
CubaPresentIntroduced Invasive Liogier, 1983; Oviedo Prieto et al., 2012
DominicaPresentIntroducedHoward, 1988
Dominican RepublicPresentIntroducedLiogier, 1983
GrenadaPresentIntroducedHoward, 1988
GuadeloupePresentIntroducedFournet, 1978
GuatemalaPresentIntroducedHolm et al., 1991
HaitiPresentIntroducedLiogier, 1983
HondurasPresentIntroducedHolm et al., 1991
JamaicaPresentIntroducedAdams, 1972
Lesser AntillesPresentIntroducedHolm et al., 1991
MartiniquePresentIntroducedFournet, 1978
MontserratPresentIntroducedHoward, 1988
Netherlands AntillesPresentIntroducedStoffers, 1980
NicaraguaPresentIntroducedSeymour, 1980
PanamaPresentIntroducedD'Arcy, 1987
Puerto RicoPresentIntroducedLiogier and Martorell, 1982
Saint LuciaPresentIntroducedHoward, 1988
Saint Vincent and the GrenadinesPresentIntroducedHoward, 1988
Trinidad and TobagoPresentIntroducedWilliams, 1928
Turks and Caicos IslandsPresentIntroducedHoward, 1988
United States Virgin IslandsPresentIntroducedLiogier and Martorell, 1982

South America

ArgentinaPresentIntroducedLegrand, 1952
BoliviaPresentIntroducedLegrand, 1952
BrazilPresentIntroducedLegrand, 1952
-Rio Grande do SulPresentIntroducedGroth, 1980
ChilePresentIntroducedPizarro, 1966
ColombiaPresentIntroducedHolm et al., 1991
EcuadorPresentIntroducedWiggins and Porter, 1971
French GuianaPresentIntroducedLemée, 1955
ParaguayPresentIntroducedHolm et al., 1991
PeruPresentIntroducedSeidenschwarz, 1986
SurinamePresentIntroducedPulle, 1906
UruguayPresentIntroducedLegrand, 1952
VenezuelaPresentIntroducedRincones, 1992

Europe

AlbaniaPresentWalters, 1964
AustriaPresentIntroducedWalters, 1964
BelgiumPresentIntroducedWalters, 1964
BulgariaPresentIntroducedKoleshev and Zhelev, 1987
CyprusPresentIntroducedMeikle, 1977
Czech RepublicPresentIntroducedWalters, 1964
EstoniaPresentIntroducedWalters, 1964
FinlandPresentIntroducedUotila, 1977
FrancePresentIntroducedWalters, 1964
-CorsicaPresentIntroducedWalters, 1964
GermanyPresentIntroducedWalters, 1964
GreecePresentIntroducedWalters, 1964
HungaryPresentIntroducedWalters, 1964
ItalyPresentIntroducedWalters, 1964
-SardiniaPresentDanin et al., 2012
LatviaPresentIntroducedWalters, 1964
NetherlandsPresentIntroducedWalters, 1964
NorwayPresentIntroducedLid and Lid, 1994
PolandPresentIntroducedWalters, 1964
PortugalPresentIntroducedWalters, 1964; Vasconcelos, 1989
Russian FederationPresentIntroducedWalters, 1964
-Central RussiaPresentIntroducedKomarov and, 1936
-Russia (Europe)PresentIntroducedKomarov and, 1936
-Russian Far EastPresentIntroducedKomarov and, 1936
SpainPresentIntroducedCarretero, 1989
-Balearic IslandsPresentIntroducedWalters, 1964
SwitzerlandPresentIntroducedWalters, 1964
UKPresentIntroducedWalters, 1964
Yugoslavia (former)PresentIntroducedWalters, 1964

Oceania

AustraliaPresentPresent based on regional distribution.
-Australian Northern TerritoryPresentIntroducedJessop, 1981
-New South WalesPresentIntroducedJessop, 1981
-QueenslandPresentIntroducedJessop, 1981
-South AustraliaPresentIntroducedJessop, 1981
-TasmaniaPresentIntroducedJessop, 1981
-VictoriaPresentIntroducedJessop, 1981
-Western AustraliaPresentIntroducedJessop, 1981
FijiPresentIntroducedHolm et al., 1991
Micronesia, Federated states ofPresentIntroducedHolm et al., 1991
New ZealandPresentIntroducedHolm et al., 1991

History of Introduction and Spread

Top of page The region of origin is uncertain, possibly an arid climate such as North Africa (Chapman et al., 1974). Although spred to the New World was thought to have been due to post-Columbian humans (Matthews et al., 1993), archaeological evidence (pollen analysis) suggests that P. oleracea arrived in the New World in pre-Columbian times (McAndrews, 1975).

Habitat

Top of page P. oleracea is common in fields, gardens, vineyards, lawns, driveways, dunes, beaches, salt marshes, waste areas, eroded slopes, bluffs and riverbanks.

Habitat List

Top of page
CategorySub-CategoryHabitatPresenceStatus
Terrestrial
 
Terrestrial – ManagedCultivated / agricultural land Present, no further details Harmful (pest or invasive)
Protected agriculture (e.g. glasshouse production) Present, no further details Harmful (pest or invasive)
Managed forests, plantations and orchards Present, no further details Harmful (pest or invasive)
Managed grasslands (grazing systems) Present, no further details Harmful (pest or invasive)
Disturbed areas Present, no further details Harmful (pest or invasive)
Rail / roadsides Present, no further details Harmful (pest or invasive)
Urban / peri-urban areas Present, no further details Harmful (pest or invasive)
Terrestrial ‑ Natural / Semi-naturalNatural forests Present, no further details Harmful (pest or invasive)
Natural grasslands Present, no further details Harmful (pest or invasive)
Riverbanks Present, no further details
Wetlands Present, no further details Harmful (pest or invasive)
Littoral
Coastal areas Present, no further details Harmful (pest or invasive)

Hosts/Species Affected

Top of page P. oleracea competes for resources with many field crops, particularly herbaceous species that are germinating or growing in competition. Affected crops include: asparagus, red beets, celery, crucifers, cotton, maize, onions, potatoes, rice, soyabeans, sugarcane, tomatoes and wheat.

Host Plants and Other Plants Affected

Top of page

Biology and Ecology

Top of page Genetics

Cytologically, P. oleracea is characterized by a sequence of polyploids, from a base number of x=9. There are diploid races (2n=18) in Africa, Central and North America; tetraploid races (2n=36) in India, Central and North America and hexaploid races (2n=54) in India, Africa, Europe, North America and Hawaii. There are additional reports of 2n=45 in India and 2n=52 in Japan. For further information see Hagerup (1932), Cooper (1935), Sugiura (1936), Steiner (1944), Heiser and Whitaker (1948), Sharma and Bhattacharyya (1956), Mulligan (1961), Walters (1964), Bouharmont (1965), Khullar and Dutta (1973), Danin et al. (1978), Sanjappa (1978), Boquar (1986), Danin and Anderson (1986), Nyananyo and Okoli (1987), Kim and Carr (1990b), Matthews et al. (1993).

Physiology, Phenology and Reproductive Biology

P. oleracea is mostly an annual, but it may be perennial in the tropics. From a typical, open, disturbed habitat purslane grows rapidly, producing flowers, fruits and seeds within 6 weeks of germination. It has a wide tolerance of photoperiod, light intensity, temperature, moisture and soil type. Seeds germinate under conditions that enhance the survival of seedlings. The species is self-compatible.

Purslane reproduces primarily from seed. Over 6000 seeds can be produced after the first flush of flowers (5-6 weeks of growth). One plant can produce between 100,000 and 242,000 seeds over an entire season. A germination rate of over 90% has been recorded after 2.5 years and other germination studies have shown 39% germination after 0.2 years, 78% after 1 year, 59% after 7 years, and 59% after 14 years; 40-year-old seeds were viable. Over 60% of seed remains viable after passage through a house sparrow (Passer domesticus).

Light is required for germination, but the temperature requirement is variable. Seeds can germinate at 10°C in the northern USA and in India, seeds germinate over the range 10-40°C, but not above 50°C. Germination response to light and temperature varies according to the site of origin and the time of seed maturation. In the dry season, seeds that developed on the upper 20% of the plant were less dormant than seeds from the lower 20%. El-Keblawy and Al-Ansari (2000) investigated the effects of site of origin, time of seed maturation and seed age on germination behaviour.

The temperature below which development of P. oleracea ceases was determined by Steinmaus et al. (2000). Kruk and Benech Arnold (1998) modelled thermal responses in Argentina. Results allowed the determination of seed germination models that predict the occurrence of seedling emergence in the field and the dynamics of seed dormancy within those periods. P. oleracea seedlings can represent about 15% of the seed bank each year in the Corn Belt of the USA.

Vegetative reproduction can occur by the development of adventitious roots from the base of cut shoots, but there is no evidence of adventitious rooting from unwounded shoots.

After germination, purslane branches almost immediately. Flowers can be produced in day lengths from 4-24 hours. There is no flowering photoperiod. Capsule production and overall plant growth increase with day length. Capsules can mature under soil conditions of high or low moisture. Flowers will not open on cloudy days or days when the temperature is below 21°C. When opened, they remain open for four hours. The flowers are self-fertile and do not exhibit apomixis. No insect pollinators have been observed during a three-year study. Some investigators have said that the flowers are wind-pollinated, but the pollen is very sticky, a characteristic that is not present in windborne pollen.

Environmental Requirements

C4 metabolism allows P. oleracea to optimize photosynthesis in conditions of high heat and bright sunlight while enduring periods of limited water availability (Koch and Kennedy, 1982). Lara et al. (2003) suggested that there is an induction of a Crassulacean acid-like metabolism (CAM) after 21-23 days of drought stress in P. oleracea.

Rainfall Regime

Top of page Summer

Soil Tolerances

Top of page

Soil drainage

  • free

Soil reaction

  • acid
  • neutral

Soil texture

  • heavy
  • light
  • medium

Special soil tolerances

  • shallow

Natural enemies

Top of page
Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Baris arctithorax Herbivore Stems
Bipolaris indica Pathogen Leaves
Ceutorhynchus portulacae Herbivore
Dichotomophthora indica Pathogen
Dichotomophthora portulacae Pathogen Leaves/Stems
Drechslera portulacae Pathogen Seedlings
Heliodines quinqueguttata Herbivore
Hypurus bertrandi Herbivore Fruits/pods/Leaves/Seeds/Stems California
Hypurus portulaceae Herbivore
Nysius vinitor Herbivore Seeds
Pegomya rufescens Herbivore
Schizocerella pilicornis Herbivore Leaves California

Notes on Natural Enemies

Top of page The natural enemies of P. oleracea listed refer to recent investigations aimed at finding biological control agents; it is premature at this stage to indicate their importance. For further investigations into the potential for biocontrol of this weed see Zakharyan and Akopyan (1974); Gadoury and Watson (1987); Waterhouse (1993).

The insects include Schizocerella pilicornis, Hypurus bertrandi, Nysius vinitor and Baris arctithorax. Their primary activity involves leaf mining, with some activity on the external parts of leaves, stems and fruits.

For further information, see Norris (1985), Awadallah et al. (1976a, b), Elshafie (1976), Gorske and Hoppen (1976), Gorske et al. (1976), and Clement and Norris (1982).

Fungi

Fungal infections include Dichotomophthora portulacae, Drechslera indica, Helminthosporium portulacae [Drechslera portulacae] and several strains of Actinomycetes.

For further information, see Norris (no date), Klisiewicz et al. (1983), Strider and Chi (1984), Vegh and LeBerre (1984), Klisiewicz (1985), Baudoia (1986), Mitchell (1986), Evans (1987), Kenfield et al. (1989) and Sugawara et al. (1992).

Plant Trade

Top of page
Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
Growing medium accompanying plants
True seeds (inc. grain) Pest or symptoms not visible to the naked eye but usually visible under light microscope
Plant parts not known to carry the pest in trade/transport
Bark
Bulbs/Tubers/Corms/Rhizomes
Flowers/Inflorescences/Cones/Calyx
Fruits (inc. pods)
Leaves
Roots
Seedlings/Micropropagated plants
Stems (above ground)/Shoots/Trunks/Branches
Wood

Impact Summary

Top of page
CategoryImpact
Animal/plant collections Negative
Animal/plant products Negative
Biodiversity (generally) None
Crop production Negative
Environment (generally) None
Fisheries / aquaculture None
Forestry production Negative
Human health Positive
Livestock production Negative
Native fauna None
Native flora None
Rare/protected species None
Tourism None
Trade/international relations None
Transport/travel None

Impact

Top of page P. oleracea is an aggressive weed in most agricultural settings. Seeds on or near the surface of the soil germinate rapidly following ploughing (seeds require light for germination), so there is immediate competition with newly sown crops. This rapid growth is usually horizontal, covering the surface of the soil. Yields can be reduced by 20-40%, depending on the crop. Purslane grows best under warm conditions, so crops in subtropical areas are affected more than those in temperate areas.

A field experiment was conducted in China to determine the relationship between the yield loss of summer maize and infestations of P. oleracea. Weed infestations did not significantly affect grain weight or ear number of the maize. The relationship between yield loss and the density of P. oleracea was S-shaped (Ni HanWen et al., 2000).

Field experiments were conducted in Brazil to determine the effect of different periods of weed competetion on groundnuts. The presence of weeds including P. oleracea resulted in decreased pod and kernel yields and groundnut dry matter (Kasai et al., 1997).

Reservoir for Other Pests

Purslane can also act as a reservoir for other diseases, particularly those caused by nematodes and some viruses.

For further information on nematodes, see Ferraz et al. (1978), Bendixen (1982), Kholod (1983), Zem and Lordello (1983), Khan and Khan (1985), Maqbool et al. (1986), Izquierdo et al. (1987), Tedford and Fortnum (1988), Inserra et al. (1989), Dabaj and Jenser (1990), Zehr et al. (1990), Salawu and Afolabi (1994).

For further information on viruses, see Locatelli et al. (1976), Pochard (1977), Locatelli et al. (1978), Dodds and Taylor (1980), Allen et al. (1983), Nasser and Basky (1988), Dikova (1989), van Os et al. (1993), Stevens et al. (1994).

Threatened Species

Top of page
Threatened SpeciesConservation StatusWhere ThreatenedMechanismReferencesNotes
Panicum fauriei (Carter's panicgrass)NatureServe NatureServe; USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiCompetition (unspecified)US Fish and Wildlife Service, 2011
Scaevola coriacea (dwarf naupaka)NatureServe NatureServe; USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiCompetition (unspecified)US Fish and Wildlife Service, 2010a
Schiedea verticillataUSA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiCompetition - monopolizing resourcesUS Fish and Wildlife Service, 2009
Sesbania tomentosaNational list(s) National list(s); USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiCompetition - monopolizing resources; Ecosystem change / habitat alterationUS Fish and Wildlife Service, 2010b

Risk and Impact Factors

Top of page Invasiveness
  • Invasive in its native range
  • Proved invasive outside its native range
  • Highly adaptable to different environments
  • Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
  • Has high reproductive potential
  • Has propagules that can remain viable for more than one year
Impact outcomes
  • Ecosystem change/ habitat alteration
  • Negatively impacts agriculture
Impact mechanisms
  • Competition - monopolizing resources
  • Competition
  • Pest and disease transmission
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Difficult to identify/detect as a commodity contaminant
  • Difficult/costly to control

Uses

Top of page P. oleracea appears to be an excellent candidate for inclusion in saline drainage water reuse systems (Grieve and Suarez, 1997). It is highly tolerant of both chloride- and sulphate-dominated salinities, is a moderate selenium accumulator and a valuable vegetable crop for human consumption (Bianco et al., 1998) and for livestock forage. It is also a source of a gum with emulsification properties that can be used in the food industry (Garti et al., 1999).

P. oleracea is a common weed in Australia and can be used as a demulcent, diuretic, antinflammatory and antibiotic (Cowper, 1996).

Uses List

Top of page

Animal feed, fodder, forage

  • Fodder/animal feed

Human food and beverage

  • Vegetable

Materials

  • Poisonous to mammals

Medicinal, pharmaceutical

  • Traditional/folklore

Similarities to Other Species/Conditions

Top of page .

Prevention and Control

Top of page

Introduction

The fleshiness of this weed makes it very resistant to desiccation, and hence often inadequately controlled by hoeing.

Physical control can be by mechanical means (Miyanishi and Cavers, 1981) or by the use of polyethylene film mulches to prevent germination (Inada et al., 1973; Kang et al., 1986; Ricotta and Masiunas, 1991; Zhang et al., 1992).

The natural enemies of P. oleracea listed refer to recent investigations aimed at finding biological control agents; it is premature at this stage to indicate their importance. For further investigations into the potential for biocontrol of this weed see Zakharyan and Akopyan (1974); Gadoury and Watson (1987); Waterhouse (1993); however, the primary method of control appears to be by chemical means.

Chemical Control

Atrazine, bentazone, bromoxynil, chloramben, chlorbufam, chlorpropham, chlorsulfuron, clomazone, clopyralid, dimethametryn, diuron, fluazifop-butyl, fluroxypyr, imazethapyr, linuron, methabenzthiazuron, metolachlor, metribuzin, napropamide, naptalam, oxadiazon, oxyfluorfen, pendimethalin, piperophos, pretilachlor, prodiamine, propanil, sethoxydim, simazine, thiazopyr and trifluralin have been used in attempts to control P. oleracea; this list is derived from hundreds of field trial reports, involving preplanting, pre-emergent and post-emergent treatments (concentrations and combinations of different chemicals are available in the literature).

The application of imazaquin, sulfentrazole and diclosulam pre-emergence; propaquizafop post-emergence followed by oxasulfuron + lactofen; haloxyfop followed by chlorimuron + lactofen gave good control of P. oleracea in soyabean (Laca Buendia et al., 1999).

Flumetsulam + trifluralin were more than 90% efficient in controlling P. oleracea with no apparent phytotoxicity (Jovanovic Radovanov et al., 1999).

Selected references for crops used in tests of herbicides to control P. oleracea:

Asparagus: Granier (1990)
Bananas: de Almeida and Texeira (1974)
Celery: Dusky (1983)
Maize: Kahurananga et al. (1973)
Cotton: Quinones (1987); Ramesh-Babu and Rao (1993)
Crucifers: Marion et al. (1985); Sieczka and Creighton (1985)
Onions: Blanco et al. (1982); Deuber et al. (1983)
Potatoes: Shehata et al. (1990)
Rice: dos Santos and Garcia (1983)
Soyabeans: William and Chiang (1976); Gazziero (1982); Gazziero et al., 1983)
Sugarcane: Kuntohartono and Tarmani (1980); Webb and Feez (1987)
Tomatoes: Rizzotto (1972); Acosta (1981)
Wheat: CIMMYT report on wheat improvement in 1979 (1981).

Herbicide Resistance

Greenhouse experiments were conducted to confirm and quantify linuron resistance in P. oleracea collected from a carrot field in Michigan, USA. A preliminary evaluation was made using a flotation test kit to identify resistance to linuron and atrazine. Subsequent greenhouse experiments indicated that P. oleracea was resistant to certains rates of linuron and atrazine. The resistant P. oleracea was also highly resistant to diuron, cyanazine and prometryn but had a low level of cross resistance bromoxynil. Both resistant and susceptible biotypes of P. oleracea were sensitive to hexazinone and bentazone (Masabni and Zanstra, 1999a, b).

Cross resistance to triazines, ureas and amides has been reported (Heap, 2000).

Allelopathy

An infusion of rue (Ruta graveolens) was tested for inhibitory effects on germination and growth of the radicle of P. oleracea. The rue infusion and its isolated allelochemicals (5-methoxysporalen, 8-methoxysporalen and quercetin) delayed the onset of germination and decreased germination. It also damaged the radicle of P. oleracea seedlings (Aliotta et al., 1996). These findings offer some promise in the search for natural herbicides.

References

Top of page

Acosta M T, 1981. Trial with ten herbicides at various rates in direct-drilled tomatoes in the plains of Guadiana, 1977. Ensayo a dosis variables, de diez herbicidas para la siembra directa del tomate en las vegas de Guadiano ano 1977. [Paper given at] Herbicidas en Hortofruticultura. XIII Jornadas de Estudio de la Asociacion Interprofesional para el Desarrollo Agrario 1981., 17 pp.

Adams CD, 1972. Flowering Plants of Jamaica. University of the West Indies, 267.

Aksoy U, Kayikcioglu H, Kukul YS, Hepaksoy S, Can HZ, Balci B, Duzyaman E, Tuzel Y, 2003. An environmentally friendly technique to control salination: salt removing crops. Proceedings of the international symposium on sustainable use of plant biodiversity to promote new opportunities for horticultural production development, Antalya, Turkey, 6-9 November, 2001. Acta Horticulturae, No. 598:137-142.

Alavi A, 1990. The role of alternative hosts in overwintering of Phytophthora drechsleri. Applied Entomology and Phytopathology, 57(1-2):21-22 (En), 77-86 (P

Aliotta G, Cafiero G, Feo Vde, Palumbo AD, Strumia S, 1996. Infusion of rue for control of purslane weed: biological and chemical aspects. Allelopathy Journal, 3(2):207-216; 32 ref.

Allen TC, McMorran JP, Locatelli EA, 1983. Isolation of tomato spotted wilt virus from hydrangea and four weed species. Plant Disease, 67(4):429-431

Almeida FS de, Texeira V, 1974. Weed control in banana fields in the Marracuene region. Boletim Informativo, Associacao de Fomenta Agricola e Industrial de Mocambique, 8(80):16-18

Anandi S, Thangavel P, Subburam V, 2002. Influence of aluminium on the restoration potential of a terrestrial vascular plant, Portulaca oleracea L. as a biomonitoring tool of fresh water aquatic environments. Environmental Monitoring and Assessment, 78(1):19-29.

Attalla SI, 2002. Weed survey in autumn planting of sugar cane at Esna district-Qena Governorate. Bulletin of Faculty of Agriculture, Cairo University, 53(3):389-410; 21 ref.

Awadallah KT, Tawfik MFS, Shalaby FF, 1976. Notes on the life-history of Baris arctithorax Pic on the weed Portulaca oleraceae L. (Coleoptera: Curculionidae). Bulletin of the Entomological Society of Egypt, No. 60:35-43

Awadallah KT, Tawfik MFS, Shalaby FF, 1976. The life-history of Hypurus bertrandi Perris (Coleoptera: Curculionidae). Bulletin of the Entomological Society of Egypt, No. 60:45-52

Azania AAPM, Azania CAM, Alves PLCA, Palaniraj R, Kadian HS, Sati SC, Rawat LS, Dahiya DS, Narwal SS, 2003. Allelopathic plants. 7. Sunflower (Helianthus annuus L.). Allelopathy Journal, 11(1):1-20; 55 ref.

Backer CA, Bakhuizen van den Brink RC, 1963. Flora of Java. Groningen, The Netherlands: NV Noordhoff, 218.

Baker JG, 1877, reprint 1970. Flora of Mauritius and the Seychelles. Cramer, 125.

Banerjee G, Mukherjee A, 2002. Biological activity of a common weed - Portulaca oleracea L. II. Antifungal activity. Acta Botanica Hungarica, 44(3/4):205-208; 6 ref.

Baudoin ABAM, 1986. First report of Dichotomophthora indica on common purslane in Virginia. Plant Disease, 70(4):352

Bendixen LE, unda. Arthropods and nematodes to which the worst annual weeds in the world act as hosts. Abstracts of the 14th Brazilian congress on herbicides and herbaceous weeds (SBHED) and the 6th congress of the Latin American Weed Association (ALAM), Campinas, 1982 Campinas, Sao Paulo, Brazil, 13-14

Bhandari MM, 1978. Flora of the Indian Desert. Jodhpur, India: Scientific Publishers, 51.

Bianco VV, Santamaria P, Elia A, Rubatzky VE (ed. ), Chen Hang (ed.), Peron JY, 1998. Nutritional value and nitrate content in edible wild species used in southern Italy. Acta Horticulturae, No. 467, 71-87.

Blanco HG, Rozanki A, Leiderman L, 1982. Experimentation with herbicides in the cultivation of onion (Allium cepa L.) to evaluate the efficiency of 16 herbicides applied pre-emergence to weeds. Biologico, 48(5):113-134

Blundell M, 1992. Wild Flowers of East Africa. London, UK: Harper Collins.

Booth BD, Murphy SD, Swanton CJ, 2003. Weed ecology in natural and agricultural systems. Weed ecology in natural and agricultural systems, viii + 303 pp.; many ref.

Boquar SR, 1986. Cytotaxonomic studies of the famly Portulacaceae from Nigeria. La Kromosoma II, 41:1255-1262.

Bouharmont J, 1965. Note sur la cytologie del quelques especies de Portulaca. Bulletin de la Societe Royale Botanique de Belgique, 98:175-188.

Boulos L, 1983. Medicinal plants of North Africa. Algonac, Michigan, USA: Reference Publications, Inc. 286 pp.

Bown D, 1995. The Royal Horticultural Society encyclopedia of herbs & their uses. London, UK: Dorling Kindersley.

Britton NL, 1918. Flora of Bermuda. New York, USA: Charles Scribner's Sons. 585 pp.

Broun AF, Massey RE, 1929. Flora of the Sudan. London, UK: Sudan Government House.

Burger WC, 1971. Flora Costaricensis. Fieldiana, Bot. No. 35:219.

Byrne R, McAndrews JH, 1975. Pre-Columbian purslane (Portulaca oleracea L.) in the New World. Nature, 253(5494):726-727.

California Invasive Plants Council, 2004. Cal IPC list. California, USA. World Wide Web page at http://groups.ucanr.org/ceppc/Pest_Plant_List.

Carretero JL, 1989. The cropland weeds of the Valencian community (Spain). Proceedings of the 4th EWRS symposium on weed problems in Mediterranean climates. Vol. 2. Problems of weed control in fruit, horticultural crops and rice., 99-112; 19 ref.

Chapman J, Stewart RB, Yarnell RA, 1974. Archaeological evidence for pre-Columbian introduction of Portulaca oleracea and Mullugo verticillata into eastern North America. Economic Botany, 28:411-412.

Chaudhary SA, Parker C, Kasasian L, 1981. Weeds of Central, Southern and Eastern Arabian Peninsula. Tropical Pest Management, 27(2):181-190.

Chivasa S, Ekpo EJA, Hicks RGT, 2002. New hosts of Turnip mosaic virus in Zimbabwe. Plant Pathology, 51(3):386; 4 ref.

CIMMYT, 1979. CIMMYT report on wheat improvement El. Batan, Mexico, 190. Weed Control, 104-109.

Clement SL, Norris RF, 1982. Two insects offer potential biological control of common purslane. California Agriculture, 36(3/4):16-18

Cooper DC, 1935. Microsporogenesis and the development of the male gametophyte in Portulaca oleracea. American Journal of Botany, 22:453-457.

Correll DS, Correll HB, 1982. Flora of the Bahama Archipelago. Cramer. Vaduz., 514.

Cowper A, 1996. Portulaca oleracea, purslane. Australian Journal of Medical Herbalism, 8(1):28; [1 pl.].

Dabaj KH, Jenser G, 1990. Some weed host-plants of the northern root-knot nematode Meloidogyne hapla in Hungary. Nematologia Mediterranea, 18(2):139-140

Danin A, Anderson LC, 1986. Distribution of Portulaca oleracea L. (Portulacaceae) subspecies in Florida. Sida, 11:318-324.

Danin A, Baker I, Baker HG, 1978. Cytogeography and taxonomy of the Portulaca oleracea L. polyploid complex. Israel Journal of Botany, 27(3/4):177-211

Danin A, Caria MC, Marrosu GM, Bagella S, 2012. A new species of Portulaca oleracea aggregate from Sardinia, Italy. Plant Biosystems, 146(Suppl. 1):137-141. http://www.tandfonline.com/loi/tplb20

D'Arcy WG, 1987. Flora of Panama. St. Louis, USA: Missouri Botanical Garden.

Deuber R, Fornasier JB, Lisbao RS, 1983. Effect of different herbicides on garlic and onion crops. Bragantia, 42(1):119-129

Dikova B, 1989. Wild-growing hosts of the cucumber mosaic virus. Rasteniev'dni Nauki, 26(7):57-64

Dodds JA, Taylor GS, 1980. Cucumber mosaic virus infection of tobacco transplants and purslane (Portulaca oleracea). Plant Disease, 64(3):294-296

Dusky JA, 1983. Weed management practices in celery. Proceedings, Southern Weed Science Society, 36th annual meeting, 174

El-Keblawy A, Al-Ansari F, 2000. Effects of site of origin, time of seed maturation, and seed age on germination behavior of Portulaca oleracea from the Old and New Worlds. Canadian Journal of Botany, 78(3):279-287; 37 ref.

Ellis DR, Guillard K, Adams RG, 2000. Purslane as a living mulch in broccoli production. American Journal of Alternative Agriculture, 15(2):50-59; 31 ref.

Elshafie M, 1976. Nysius vinitor Berg. (Hemiptera: Lygaeidae) infesting pigweed, Portulaca oleracea L. Journal of the Entomological Society of Australia (N.S.W.), 9:54

Emmerson FR, McKenzie RA, 1994. Stock Diseases: Pigweed poisoning. Animal and Plant Health Service, Australia. http://www.dpi.qld.gov.au/health/4219.html.

Evans HC, 1987. Fungal pathogens of some subtropical and tropical weeds and the possibilities for biological control. Biocontrol News and Information, 8(1):7-30

Ferraz LCCB, Pitelli RA, Furlan V, 1978. Nematodes associated with weeds in the Jaboticabal region. Planta Daninha, 1(1):5-11

Forcella F, Wilson RG, Dekker J, Kremer RJ, Cardina J, Anderson RL, Alm D, Renner KA, Harvey RG, Clay S, Buhler DD, 1997. Weed seed bank emergence across the Corn Belt. Weed Science, 45(1):67-76.

Fournet J, 1978. Flore illustrée des phanérogames de Guadeloupe et de Martinique. Paris, France: Institut National de la Recherche Agronomique.

Gadoury H, Watson AK, 1987. Biological control of lawn weeds. Cahier des Journees Horticoles Ornementales, III:9-15

Ganga Visalakshy PN, Krishnan S, 2001. Propagation methods of Ceutorhynchus portulacae, a potential biocontrol agent of Portulace oleracea L. procedures and cost. Entomon, 26(1):79-85; 16 ref.

Garti N, Slavin Y, Aserin A, 1999. Surface and emulsification properties of a new gum extracted from Portulaca oleracea L. Food Hydrocolloids, 13(2):145-155; 38 ref.

Gazziero DLP, 1982. Herbicide recommendations for the direct sowing method in soyabean cultivation. Comunicado Tecnico, Centro Nacional de Pesquisa de Soja, No.16:7pp.

Gazziero DLP, Almeida FS, Rodrigues BN, Oliveira VF, 1983. Recommendations for weed control in the soyabean crop. Comunicado Tecnico, Centro Nacional de Pesquisa de Soja, No.21:10pp.

Geesink R, 1969. An account of the genus Portulaca in Indo-Australia and the Pacific (Portulacaceae). Blumea, 17:274-301.

Geesink R, 1975. Portulaca, In Flora of Thailand. Bangkok, Thailand: Applied Scientific Research Corporation of Thailand.

Gooding EGB, Loveless AR, Proctor GR, 1965. Flora of Barbados. London, UK: Ministry of Overseas Development.

Gorske SF, Hopen HJ, 1976. Purslane sawfly (Schizocerella pilicornis) as a biological control agent of common purslane (Portulaca oleracea L.). HortScience, 11(3, Section 2):326

Gorske SF, Hopen HJ, Randell R, 1976. The purslane sawfly (Schizocerella pilicornis): as a biological control agent of common purslane (Portulaca oleracea L.). Proceedings North Central Weed Control Conference 1975., Vol. 30:30-31

Gorske SF, Rhodes AM, Hopen HJ, 1979. A numerical taxonomic study of Portulaca oleracea. Weed Science, 27(1):96-102

Graifenberg A, Botrini L, Giustiniani L, Filippi F, Curadi M, 2003. Tomato growing in saline conditions with biodesalinating plants: Salsola soda, and Portulaca oleracea. International Symposium on Managing Greenhouse Crops in Saline Environment. Acta Horticulturae, No. 609.

Granier A, 1990. Chemical weed control in transplanting of seedling asparagas plants. Acta Horticulturae, 271:263-266.

Grieve CM, Suarez DL, 1997. Purslane (Portulaca oleracea L.): a halophytic crop for drainage water reuse systems. Plant and Soil, 192(2):277-283; 31 ref.

Groth D, 1980. Botanical identification of plants and seeds of weeds in soyabean crops. Revista Brasileira de Sementes, 2(3):59-95.

Guillarmod AJ, 1971. Flora of Lesotho. Cramer, LEHRE.

Gunawardena DC, 1968. Genera et Species Plantarum Zeylaniae. London, UK: Lake House Investments.

Haar MJ, Fennimore SA, 2003. Evaluation of integrated practices for common purslane (Portulaca oleracea) management in lettuce (Lactuca sativa). Weed Technology, 17(2):229-233.

Haar MJ, Fennimore SA, Ajwa HA, Winterbottom CQ, 2003. Chloropicrin effect on weed seed viability. Crop Protection, 22(1):109-115; 37 ref.

Hagerup O, 1932. sber Polypoidie in Beziehung zu Klima, _kologie and Phylogenie (Chromosomenzahlen aus Timbuktu). Hereditas, 16:19-40.

Hara H, Stearn WT, Williams LHJ, 1978. An Enumeration of the Flowering Plants of Nepal. London, UK: British Museum.

Heap IM, 2000. International survey of herbicide-resistant weeds (online). WWW page at http://www.weedscience.org/Resistance/resistmodule.asp.

Heiser CB, Whitaker TW, 1948. Chromosome number, polyploidy and growth habit of California weeds. American Journal of Botany, 35:179-186.

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

Hooker WJ, 1849 (1966 reprint). Niger Flora. J. Cramer, Lehre, 173.

Howard RA, 1988. Flora of the Lesser Antilles. Vol. 1-6. Arnold Arboretum. Jamaica Plains, Massachussetts, USA: Harvard University.

Hutchinson J, Dalziel JM, 1954. 2nd edition. Flora of West Tropical Africa. Kew, UK: Royal Botanic Gardens, 137.

Inada K, Aimi R, Miwa S, et al, 1973. Photo-selective plastic film for mulch. Japan Agricultural Research Quarterly, 7:252-256.

Inserra RN, Dunn RA, McSorley R, Langdon KR, Richmer AY, 1989. Weed hosts of Rotylenchulus reniformis in ornamental nurseries of southern Florida. Nematology Circular (Gainesville), No. 171:4 pp.

ISSG, 2004. Global invasive species database entry for Eriocheir sinensis. Online at www.issg.org. Accessed 26 May, 2004.

Izquierdo JE, Huepp G, Chacon L, 1987. Detection of nematodes of the genus Meloidogyne in weeds associated with coffee plantations. Ciencia y Tecnica en la Agricultura, Cafe y Cacao, 9(1):47-54.

Jeanplong J, 1973. Investigation of the weed flora of North Vietnam. Botanikai Kozlemenyek, 60(3):167-175.

Jensen KI, 1978. Postemergence herbicides for peas. In: Expert Committee on Weed Research Report, Eastern Section. Canada: Agriculture Canada, 59.

Jessop J, 1981. Flora of Central Australia. Australia: Australian Systematic Botany Society, 41.

Jovanovic-Radovanov K, Drndarevic A, Elezovic I, 1999. Investigation of flumetsulam efficacy in combination with alachlor and trifluralin in maize and soyabean crops. Pesticidi, 14(2):165-176; 9 ref.

Kahurananga J, Magambo M, Mosha CJ, Sambai L, 1973. The effect of 5 herbicides on broad-leaved weed density and dry matter yield of maize. Miscellaneous Report, East African Community Tropical Pesticides Research Institute, No. 815:8 pp.

Kang CK, Oh SM, Choi YC, Lee KH, 1986. Studies on the weed control and phytotoxity of herbicides under polyethylene film mulching in the red pepper (Capsicum annuum L.) upland. Korea Republic. Research Reports of the Rural Development Administration, Plant Environment, Mycology and Farm Product Utilization, 28:72-78.

Kasai FS, Paulo EM, Cavichioli JC, Peressin VA, Igue T, 1997. Effects of weed competition periods on peanut crop: dry season peanut of 1988. Bragantia, 56(2):323-331; 23 ref.

Kenfield D, Hallock Y, Clardy J, Strobel G, 1989. Curvulin and O-methylcurvulinic acid: phytotoxic metabolites of Drechslera indica which cause necroses on purslane and spiny amaranth. Plant Science, Irish Republic, 60(1):123-127

Khan RM, Khan MW, 1985. Portulaca oleracea hitherto unrecorded host of Rotylenchulus reniformis from India. Acta Botanica Indica, 13(2):285-286

Kholod NA, 1983. Plant hosts of the strawberry nematode. Steblevye nemotody sel'skokozyaistvennykh kul'tur i mery bor'by s nimi. Materialy simpoziuma, Voronezh, 27-29 Sentyabrya 1983 g. Voronezh, USSR: Vserossiiskii Nll Zashchity Rastenii, 104-111.

Khullar SP, Dutta M, 1973. Cytotaxonomic studies on the genus Portulaca from Chandigarh North India. Bangladesh Journal of Botany, 2:95-102.

Kim I, 1989. Biosystematics and ultrastructure of Portulaca in Hawaii, PhD dissertation. Ann Arbor, Michigan, USA.

Kim I, Carr GD, 1990. Cytogenetics and hybridization of Portulaca in Hawaii. Systematic Botany, 15(3):370-377

Kim I, Carr GD, 1990. Reproductive biology and uniform culture of Portulaca in Hawaii. Pacific Science, 44:123-129.

Kim IS, 1993. Biosystematics of Portulaca species in Northeast Asia. Korean Journal of Plant Taxonomy, 23(2):71-96

Kitamura S, 1960. Flora of Afghanistan. Kyoto University Scientific Expedition to the Karakoram and Hindukush. Kyoto University.

Klisiewicz JM, 1985. Growth and reproduction of Dichotomophthora portulacp and its biological activity on purslane. Plant Disease, 69(9):761-762

Klisiewicz JM, Clement SL, Norris RF, 1983. Black stem: a fungal disease of common purslane in California. Plant Disease, 67(10):1162

Koch KE, Kennedy RA, 1982. Crassulacean acid metabolism in the succulent C4 dicot, Portulaca oleracea L. under natural environmental conditions. Plant Physiology, 69(4):757-761

Koleshev V, Zhelev A, 1987. Potential and actual weed infestation of areas used for vegetable seedling production. Pochvoznanie, Agrokhimiya i Rastitelna Zashchita, 22(4):91-95; 16 ref.

Komarov VL, ed. , 1936. Flora of the USSR. (1970 translation, Israel Program for Scientific Translations for the Smithsonian Institution, Washington), (VI):296.

Kruk BC, Benech-Arnold RL, 1998. Functional and quantitative analysis of seed thermal responses in prostrate knotweed (Polygonum aviculare) and common purslane (Portulaca oleracea). Weed Science, 46(1):83-90; 26 ref.

Kuntohartono T, Tarmani P, 1980. Weeds of mechanized sugarcane field in Java: their economic importance and control. Seventeenth Congress of the International Society of Sugar Cane Technologists. Volume I. ISSCT. Manila Philippines, 336-349

Lara M, Disante K, Podestá F, Andreo C, Drincovich M, 2003. Induction of a Crassulacean acid like metabolism in the C4 succulent plant, Portulaca oleracea L.: physiological and morphological changes are accompanied by specific modifications in phosphoenolpyruvate carboxylase. Photosynthesis Research, 77(2/3):241-254.

Legrand CD, 1952. Revisando tipos de Portulaca. Comun. Bot. del Museo de Historia Natural de Montevideo, 24:1-11.

Legrand CD, 1962, Las especies Americanas de Portulaca. Anales del Museo de Historia Natural de Montevideo. II.

Leguizam=n ES (ed.), 2000. Lista florfstica / Control obtenido con glifosato. Jornada interactiva sobre malezas y soja, Cßtedra de Malezas, Facultad de Ciencias Agrarias, UNR, Argentina.

LemTe A, 1955. Flore de la Guyane francaise. Paris.

Leyel CF, 1987. Herbal Delights. Faber and Faber.

Li HL, 1975-79. Flora of Taiwan. Taipei, Taiwan: Epoch, 2:316.

Lid J, Lid ET, 1994. Norsk Flora. Oslo, Norway: Det Norske Sam Laget.

Liogier HA, 1983. La flora de la Espa_ola. San Pedro de Macoris, Santa Domingo, Dominican Republic. Universidad Central Del Este, (44).

Liogier HA, Martorell LF, 1982. Flora of Puerto Rico and Adjacent Islands. Editorial de la Universidad de Puerto Rico, 46.

Locatelli E, Appleby AP, Allen TC, Weeds as carriers of viruses: detection of viruses in weeds and crop plants in potato growing districts of Oregon State, with special reference to TRV (tobacco rattle virus) and PVX (potato virus X). Trabajos y Resumenes, III Congreso Asociacion Latinoamericana de Malezas "ALAM" y VIII Reunion Argentina de Malezas y su Control, "ASAM", Mar del Plata, 1976. ASAM. 1356 Av. Corrientes 123, Buenos Aires Argentina, Vol. 1:132-133

Locatelli EA, Allen TC, Koepsell PA, Appleby AP, 1978. Diagnosis of tobacco rattle virus (TRV) and other viruses in weed and rotation crops in potato fields. American Potato Journal, 55(5):249-257

Maqbool MA, Hashmi S, Ghaffar A, 1986. Eleven new hosts of root-knot nematodes and identification of physiological races in Pakistan. Pakistan Journal of Nematology, 4:11-14.

Marion GR, Ilnicki RD, Kupatt C, Vitolo DB, 1985. Weed control in transplanted cole crops with some new herbicides. Proceedings 39th annual meeting of the Northeastern Weed Science Society, 147-150

Masabni JG, Zandstra BH, 1999. A serine-to-threonine mutation in linuron-resistant Portulaca oleracea. Weed Science, 47(4):393-400; 45 ref.

Masabni JG, Zandstra BH, 1999. Discovery of a common purslane (Portulaca oleracea) biotype resistant to linuron. Weed Technology, 13(3):599-605; 19 ref.

Matthews JF, Ketron DW, Zane SF, 1993. The biology and taxonomy of the Portulaca oleracea L. (Portulacaceae) complex in North America. Rhodora, 95(882):166-183

Meikle RD, 1977. Flora of Cyprus. Kew, UK: Bentham-Moxon Trust.

Merrill ED, 1912. A Flora of Manila. Manila Bureau of Printing, 200.

Mitchell JK, 1986. Dichotomophthora portulacp causing black stem rot on common purslane in Texas. Plant Disease, 70(6):603

Mitich LW, 1997. Common purslane (Portulaca oleracea). Weed Technology, 11(2):394-397; 31 ref.

Miyanishi K, Cavers PB, 1980. The biology of Canadian weeds. 40. Portulaca oleracea L. Canadian Journal of Plant Science, 60(3):953-963

Miyanishi K, Cavers PB, 1981. Effects of hoeing and rototilling on some aspects of the population dynamics of pure stands of Portulaca oleracea L. (purslane). Weed Research, 21(2):47-58

Montemurro P, Fracchiolla M, 2000. Preliminary results on the use of azafenidin in weed control of olive orchard. Atti, Giornate fitopatologiche, Perugia, 16-20 aprile, 2000, Volume 2, 525-530; 3 ref.

Mouterde P, 1966. Nouvelle flore du Liban et de la Syrie. Beyrouth: Editions De L' Imprimerie Catholique.

Muenscher WC, 1955. Weeds, 2nd edition. New York, USA: Macmillan, 560 pp.

Mulligan GA, 1961. Chromosome numbers of Canadian weeds. Canadian Journal of Botany, 50:1767-1771.

Nasser MAK, Basky Zs, 1988. Research on some weeds as reservoirs of cucumber mosaic virus. Zoldsegtermesztesi Kutato Intezet Bulletinje, 21:83-88

Ni HanWen, Zhang Li, Chen Yong, Li ShanLin, 2000. Yield loss model due to the infestation of weeds in summer maize. Acta Phytophylacica Sinica, 27(2):163-167; 10 ref.

Norris RF, unda. Biological weed control with endemic organisms, with emphasis on common purslane (Portulaca oleracea). Proceedings, 37th annual California weed conference El Macero, California, USA, 67-69

Novoplansky A, 1991. Developmental responses of portulaca seedlings to conflicting spectral signals. Oecologia, 88(1):138-140

Nyananyo L, Okoli BE, 1987. Cytological and morphological studies on Nigerian species of Portulaca (Portulacaceae) in relation to their taxonomy. Feddes Repertorium, 98:583-587.

Obied WA, Mohamoud EN, Mohamed OSA, 2003. Portulaca oleracea (purslane): nutritive composition and clinico-pathological effects on Nubian goats. Small Ruminant Research, 48(1):31-36; 23 ref.

Ohwi J, 1965. Flora of Japan. Washington, DC., USA: Smithsonian Institution.

Os B van, Stancanelli G, Mela L, Lisa V, 1993. Role of wild plants and weeds in the epidemiology of tospovirus in Liguria. Informatore Fitopatologico, 43(10):40-44

Oviedo Prieto R, Herrera Oliver P, Caluff MG, et al. , 2012. National list of invasive and potentially invasive plants in the Republic of Cuba - 2011. (Lista nacional de especies de plantas invasoras y potencialmente invasoras en la República de Cuba - 2011). Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba, 6(Special Issue 1):22-96.

Palaniswamy UR, McAvoy RJ, Bible BB, 2001. Omega-3 fatty acid concentration in purslane (Portulaca oleraceae) is altered by photosynthetic photon flux. Journal of the American Society for Horticultural Science, 126(5):537-543; 40 ref.

Pancho JV, 1986. Weeds of vegetable farms in the highlands of Luzon, La Trinidad, Benguet, Philippines. Biotrop Special Publication, No. 24:117-121

Partha Ghosh, Bhattacharya SP, Pal P, 2000. Efficacy of dazomet (Basamid-G) in seedling production and weed management in Dianthus, sweet Willium [sweet William] and Phlox. Journal of Interacademicia, 4(4):502-505; 1 ref.

PIER, 2004. Pacific Islands Ecosystems at Risk (PIER). http://www.hear.org/pier/wra/australia/cydac-wra.htm.

Pizarro CM, 1966. Sinopsis de la flora Chilena, 2nd edition. Chile: Ediciones de la Universidad de Chile.

Ploetz R, Heine G, Haynes J, Watson M, 2002. An investigation of biological attributes that may contribute to the importance of Phytophthora capsici as a vegetable pathogen in Florida. Annals of Applied Biology, 140(1):61-67; 16 ref.

Pochard E, 1977. Study of resistance to European strains of potato virus Y (PVY) in Capsicum. In: Pochard E, ed. Capsicum 77. Proceedings of the 3rd Congress of EUCARPIA on genetics and selection of pepper Avignon-Montfavet, 5-8 July 1977.: Capsicum 77. Comptes rendus du 3 deg Congres EUCARPIA sur la genetique et la selection du piment Avignon-Montfavet, 5-8 Juillet 1977. INRA. Avignon-Montfavet France, 109-118

Poellnitz K von, 1934. Attempt at a monograph of the genus Portulaca L. (Versuch zur einer Monographie der Gattung Portulaca L.) Repertorium specierum novarum regni vegetabilis. Feddes Repertorium, 37:240-320.

Post GE, 1932. Flora of Syria, Palestine and Sinai. Beirut, Lebanon: American Univeristy of Beirut Press.

Prabhakar M, Leelavathi P, Vijay Kumar BK, 1990. SEM studies on seeds of Indian Portulacaceae and their taxonomic significance. Asian Journal of Plant Science, 2:9-14.

Prabhakar M, Ramayya N, 1988. Chemotaxonomy of the genus Portulaca L. protein and non-protein free amino acids of leaf. Indian Journal of Botany, 11(1):51-58.

Pulle A, 1906. An enumeration of the vascular plants known from Suriname together with their distributions and synonymy. Leiden: EJ Brill Ltd.

Quezel P, Santa S, 1962. Nouvelle flore de L'Algérie et des régions désertiques méridionales.

Quinones VM, 1987. Weed control in cotton (Gossypium hirsutum L.) at Barinas, Venezuela. Agronomia Tropical (Maracay), 37(4-6):23-33

Radhakrishnan R, Zakaria MNM, Islam MW, Chen HB, Kamil M, Chan K, Al-Attas A, 2001. Neuropharmacological actions of Portulaca oleraceae L v. sativa (Hawk). Journal of Ethnopharmacology, 76(2):171-176.

Ramesh Babu, Rao MVH, 1993. Evaluation of herbicides for weed control in irrigated cotton (Gossypium hirsutum L.). Integrated weed management for sustainable agriculture. Proceedings of an Indian Society of Weed Science International Symposium, Hisar, India, 18-20 November 1993 Hisar, Haryana, India; Indian Society of Weed Science, Vol. III:179-181

Reid DP, 1993. Chinese Herbal Medicine. Boston, USA: Shambhala.

Ricotta JA, Masiunas JB, 1991. The effects of black plastic mulch and weed control strategies on herb yield. HortScience, 26(5):539-541

Rincones C, 1992. Weed distribution in sugarcane fields of Carabobo state, Venezuela. Cana de Azucar, 10(1):3-19

Rizzotto N, 1972. Selective chemical weed control in direct-sown tomatoes. Informatore Agrario, 12:[3 pp.]

Rzendowski J, Rzendowski GC, 1979. Flora Fanerogamica del Valle de Mexico. Mexico: Compania Editorial Continental, (I):168.

Salawu EO, Afolabi SS, 1994. Weed hosts of a root-knot nematode, Meloidogyne incognita, at the Bacita Sugarcane Plantation, Nigeria. Pakistan Journal of Nematology, 12(1):67-71; 16 ref.

Sanjappa M, 1978. IOPB Chromosome number reports LXI. Taxon, 27:375-392.

Santos CAL dos, Garcia B H, 1983. Weeds and herbicides on rice (Oryza sativa L.) crops: trials by the herbicide section for the period 1965 to 1982. Biologico, 49(6):131-152

Seidenschwarz F, 1986. Comparison of riverside herb communities with weed vegetation in the tropical lowlands of Peru. Amazoniana, 10(1):79-111

Sertkaya G, cinar A, 2002. Detection of some weed species as host of Spiroplasma citri Saglio et al. and its insect vector Circulifer haematoceps (M.-R.) (Hom.: Cicadellidae) in the Eastern Mediterranean Region of Turkey. Tu^umlaut~rkiye Herboloji Dergisi, 5(1):35-41; 19 ref.

Seymour FC, 1980. A checklist of the vascular plants of Nicaragua. Phytologia, Memoirs I.

Sharma AK, Bhattacharyya NK, 1956. Cytogenetics of some members of Portulacaceae and related families. Caryologia, 8:257-274.

Shehata SA, El-Sayed SF, Fayad AN, 1990. Chemical weed control in potato fields. Agricultural Research Review, 68(5):1025-1039

Shukla SP, 1971. Germination behaviour of a weed and three related crop plants under various conditions of soil water content and temperature. Journal of the Indian Botanical Society, 50:727.

Singh KP, 1968. Thermoresponse of Portulaca oleracea seeds. Current Science, 38:506-507.

Singh KP, 1973. Effect of temperature and light on seed germination of two ecotypes of Portulaca oleracea L. New Phytologist, 72(2):289-295

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.

Stapleton JJ, Prather TS, Mallek SB, Ruiz TS, Elmore CL, 2002. High temperature solarization for production of weed-free container soils and potting mixes. HortTechnology, 12(4):697-700; 13 ref.

Steiner E, 1944. Cytogenetic studies on Talinum and Portulaca. Botanical Gazette, 105:374-379.

Steinmaus SJ, Prather TS, Holt JS, 2000. Estimation of base temperatures for nine weed species. Journal of Experimental Botany, 51(343):275-286; 31 ref.

Stevens M, Smith HG, Hallsworth PB, 1994. The host range of beet yellowing viruses among common arable weed species. Plant Pathology, 43(3):579-588.

Stewart RR, 1972. Flora of West Pakistan. An Annotated Catalogue of the Vascular Plants of West Pakistan and Kashmir. Michigan, USA: University of Michigan, Ann Arbor.

Stoffers AL, 1980. Flora of the Netherlands Antilles. Uitgaven "Natuurwetenschappelsjke Studieking vor Suriname en de Nederlandse Antille," Utrecht.

Strider DL, Chi TTL, 1984. Damping-off of portulaca caused by Helminthosporium (Bipolaris) portulacp in North Carolina. Plant Disease, 68(9):826

Sugawara F, Kim KW, Kobayashi K, Uzawa J, Yoshida S, Murofushi N, Takahashi N, Strobel GA, 1992. Zearalenone derivatives produced by the fungus Drechslera portulacae. Phytochemistry, 31(6):1987-1990

Sugiura TA, 1936. A list of chromosome numbers in angiospermic plants. II Proc. Imp. Acad. Tokyo, 12:144.

Tedford EC, Fortnum BA, 1988. Weed hosts of Meloidogyne arenaria and M. incognita common in tobacco fields in South Carolina. Annals of Applied Nematology, 2:102-105.

TSckholm V, 1956. Student's Flora of Egypt. Cairo: Anglo-Egyptian Bookshop.

Unger PW, Miller SD, Jones OR, 1999. Weed seeds in long-term dryland tillage and cropping system plots. Weed Research (Oxford), 39(3):213-223; 19 ref.

Uotila P, 1977. Notes on Portulaca oleracea (Portulacaceae) in Finland. Memoranda Societatis pro Fauna et Flora Fennica, No. 53:21-23

US Fish and Wildlife Service, 2009. In: Schiedea verticillata (no common name). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 13 pp.

US Fish and Wildlife Service, 2010. In: Scaevola coriacea (dwarf naupaka). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 19 pp.

US Fish and Wildlife Service, 2010. In: Sesbania tomentosa (ohai). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 24 pp.

US Fish and Wildlife Service, 2011. In: Panicum fauriei var. carteri (no common name). 5-Year Review: Summary and Evaluation. US Fish and Wildlife Service, 17 pp.

USDA, 2004. Federal Noxious Weed List. USDA, APHIS, PPQ, Riverdale, Maryland, USA. World Wide Web at:http:// www.aphis.usda.gov/ppq/permits/fnwsbycat-e.PDF.

USDA, 2004. Plants Database. World Wide Web at: http://plants.usda.gov/index.html.

Ustun NS, Tosun I, 2003. Composition of some edible wild plants of Tunceli and surroundings. Ondokuz Mayis Universitesi, Ziraat Fakultesi Dergisi, 18(2):71-75.

Vasconcelos T, 1989. Weed flora of tomato crop grown for canning in Ribatejo (Portugal): influence of edaphic factors. Proceedings of the 4th EWRS symposium on weed problems in Mediterranean climates. Vol. 2. Problems of weed control in fruit, horticultural crops and rice, 46-53

Vasilakoglou IB, Eleftherohorinos IG, 2003. Persistence, efficacy, and selectivity of amide herbicides in corn. Weed Technology, 17(2):381-388.

Vegh I, Berre ALe, 1984. Presence in France of two new diseases on common purslane and tarragon. Revue Horticole, No. 249:15-17

Vengris J, Dunn S, Stacewicz-Sopuncakis M, 1972. Life history studies as related to weed control in the northeast. 7. common purslane. Research Bulletin, Agricultural Experiment Station, University of Massachusetts, 598:1-44.

Vengris J, Stacewicz-Sopuncakis M, 1971. Common purslane competition in table beets and snap beans. Weed Science, 19(1):4-6.

Visalakshy PNG, Jayanth KP, 1996. Hypurus ? portulaceae Marshall (Coleoptera: Curculionidae) - a potential natural enemy of the purslane weed, Portulaca oleracea (L.). Pest Management in Horticultural Ecosystems, 2(1):51-52; 6. ref.

Walker GE, Cobon J, Nobbs J, 2002. New Australian record for Meloidogyne javanica on Portulaca oleracea. Australasian Plant Pathology, 31(3):301; 6 ref.

Walters SM, 1964. Portulaca L. In: Tutin TG, et al., eds. Flora Europaea, I. Cambridge.

Waterhouse DF(Editor), 1994. Biological control of weeds: Southeast Asian prospects. Canberra, Australia; Australian Centre for International Agricultural Research (ACIAR), v + 302 pp.

Waterhouse DF, 1993. Biological control: Pacific prospects - supplement 2. Canberra, Australia: ACIAR, 138 pp.

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.

Webb KR, Feez AM, 1987. Control of broadleaf weeds with fluroxypyr in sugarcane and grain sorghum in Northern New South Wales and Queensland, Australia. In: Proceedings of the 11th Asian Pacific Weed Science Society Conference Taipei, Taiwan: Asian Pacific Weed Science Society, 1:211-217.

Wiggins IL, Porter DM, 1971. Flora of the Galapagos Islands. Stanford, USA: Stanford University Press.

William RD, Chiang MY, 1976. Use of herbicides for weed control in tropical soybean production. Expanding use of soybeans. Proceedings of a conference held at Chiang Mai, Thailand, February 1976 (INTSOY Series, International Soybean Program, No. 10)., 74-81

Williams RO, 1928. Flora of Trinidad and Tobago. Port of Spain, Trinidad: Ministry of Agriculture.

Williamson M, Preston C, Telfer M, 2003. On the rates of spread of alien plants in Britain. In: Child LE, Brock JH, Brundu G, Prach K, Pysek P, Wade PM, Williamson M, eds. Plant Invasions: Ecological Threats and Management Solutions. Backhuys, Leiden, 63-74.

Yip SM, 1976. A survey of the common weed species found in vegetable fields and weed control methods adopted by farmers in Hong Kong. Agriculture Hong Kong, 1(5):434-445

Zakharyan SV, Akopyan MA, 1974. The herbicidal activity of actinomycetes. Biologicheskii Zhurnal Armenii, 27(12):89

Zehr EI, Aitken JB, Scott JM, Meyer JR, 1990. Additional hosts for the ring nematode, Criconemella xenoplax. Journal of Nematology, 22(1):86-89

Zelaya IA, Owen MDK, Pitty A, 1997. Germination characteristics of eight weed species from the dry tropics. CEIBA, 38(2):137-149; 3 pp. of ref.

Zem AC, Lordello LGE, 1983. Studies on hosts of Radopholus similis and Helicotylenchus multicinctus. Trabalhos apresentados a VII Reuniao Brasileira de Nematologia, Brasilia, DF, 21-25 de fevereiro de 1983. Publicacao No.7. Sociedade Brasileira de Nematologia Piracicaba, SP Brazil, 175-187.

Zhang BY, Chen HG, Zhou TW, 1992. Exploration on coloured plastic film mulch for controlling weeds in tomato and maize fields. Plant Protection, No. 6:40-41.

Zimmerman CA, 1976. Growth characteristics of weediness in Portulaca oleracea L. Ecology, 57(5):964-974

Zimmerman CA, 1977. A comparison of breeding systems and seed physiologies in three species of Portulaca L. Ecology, 58(4):860-868

Links to Websites

Top of page
WebsiteURLComment
GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gatewayhttps://doi.org/10.5061/dryad.m93f6Data source for updated system data added to species habitat list.
Global register of Introduced and Invasive species (GRIIS)http://griis.org/Data source for updated system data added to species habitat list.

Distribution Maps

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