Pacific Pests, Pathogens and Weeds - Online edition

Pacific Pests, Pathogens, Weeds & Pesticides

Pigweed (462)


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Summary
  • Widespread. Asia, Africa, North, South and Central America, Caribbean, Europe, Oceania. In Australia, FSM, Fiji, New Zealand, PNG.
  • Aggressive weed of vegetables, grain and plantation crops, pastures, disturbed sites, waste areas, footpaths and roadsides. Invasiveness assisted by rapid growth in variety of soils, early flowering, huge seed production, survival in soil for several years, germinating rapidly following ploughing in responses to light. Also, drought tolerant. Alternative host of nematode, virus and phytoplasma pathogens.
  • Much-branched, creeping, fleshy stem, 20-50 cm long, reddish, hairless. Leaves, alternate along stems, 5-25 mm long, hairless, wedge-shaped, without stalks (or very short). Flowers, yellow, single or in small clusters, in forks of leaves, each with 4-6 petals. Fruits contain small black seeds, glossy, warty.
  • Spread: seed; by birds; wind, water; contaminant of crop seeds.
  • Biosecurity: moderately high risk of introduction; contaminant of seed.
  • Biocontrol: weevil, Hypurus bertrandi, introduced into Hawaii, but present status unreported.
  • Cultural control: hand weed or hoe; thick mulch.
  • Chemical control: in Australia: 2,4-D; diuron; dicamba; MCPA; metsulfuron-methyl; metribuzin; pendimethalin; propyzamide; fluroxpyr; trifluralin; glyphosate (and Fiji); oxyfluorfen.
Common Name

Pigweed; it is also known as pig weed, or purslane.

Scientific Name

Portulaca oleracea. It was known previously as Portulaca officinarum. It is a member of the Portulacaeae.


AUTHORS Grahame Jackson & Aradhana Deesh
Adapted from Pigweed (Portulaca oleraceae) (2018) Weeds of SE Qld and Northern NSW. Lucidcentral. (https://www.lucidcentral.org/editors-pick-animal-and-plant-identification-keys/key-to-weeds-of-se-qld-and-northern-nsw); and additional information from CABI (2019) Portulaca oleraceae (purslane). Invasive Species Compendium. (https://www.cabi.org/isc/datasheet/43609); and from Waterhouse DF (1993) Portulaca oleraceae Linneaus. Biological Control: Pacific Prospects - Supplement 2. ACIAR Monograph No. 20. Canberra, ACT. Photo 1 Phil Westra, Colorado State University, Bugwood.org. Photo 2 ZooFari Portulaca oleraceae (Wikipedia). Photo 3 jacilluch Flower of Portulaca oleracea (Wikipedia).

Produced with support from the Australian Centre for International Agricultural Research under project HORT/2016/185: Responding to emerging pest and disease threats to horticulture in the Pacific islands, implemented by the University of Queensland, in association with the Pacific Community and Koronivia Research Station, Ministry of Agriculture, Fiji.

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