Common Name: Green Purslane

General Information

Portulaca oleracea is an erect or ascending, copiously-branched, succulent, annual to perennial plant, growing 20 - 50cm tall[].
One of the first plants to be domesticated as a food crop, purslane has become a cosmopolitan weed of tropical to warm temperate climates[]. The plant is often harvested from the wild for local use as a food and medicine, and is often sold in local markets. It is cultivated on a small scale and in home gardens for its edible leaves and is also grown as an ornamental[, ].
The plant is easily dispersed by running water, and seeds are easily spread by the wind, water, with crop seeds or through bird droppings[]. It often escapes from cultivation and has become an aggressive weed in areas where the climate suits it[].

Known Hazards

None known

Botanical References

Range

The original range of this species is uncertain, possibly western Asia or India. It is found as a weed in most areas of the world.

Habitat

Fields, waste ground, roadside verges, cultivated ground and by the sea[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Habit	Annual/Perennial
Height	0.25 m
Growth Rate	Fast
Pollinators	Insects, Self
Self-fertile	Yes
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Purslane can be cultivated from the temperate zone to the tropics so long as there is a growing season of at least 3 months. In the tropics it can be grown at elevations up to 1,700 metres. It grows best in areas where annual daytime temperatures are within the range 18 - 32°c, but can tolerate 7 - 36°c[]. It prefers a mean annual rainfall in the range 1,000 - 2,000mm, but tolerates 500 - 4,000mm[].
Requires a moist light rich well-drained soil in a sunny position[, , ]. Plants are adaptable to most soils, including mildly saline[, , ]. Established plants are drought tolerant[]. Plants will not produce good quality leaves when growing in dry conditions[]. Prefers a pH in the range 5.5 - 7, tolerating 4.3 - 8.3[].
The plants take about six to eight weeks to produce a crop from seed and can then be harvested on a cut and come again principle[].
Top yields in Europe are about 50 tonnes per hectare, whilst in the tropics yields of 12 - 17 tonnes have been reported[].
There is at least one cultivar, called 'Wildfire', that is grown as an ornamental plant[].
The flowers only open in full sunlight[].
This species photosynthesizes by a more efficient method than most plants. Called the 'C4 carbon-fixation pathway', this process is particularly efficient at high temperatures, in bright sunlight and under dry conditions[, ].

Edible Uses

Leaves and stems - raw or cooked[, , , , ]. The young leaves are a very acceptable addition to salads, their mucilaginous quality also making them a good substitute for okra as a thickener in soups[, ]. Older leaves are used as a potherb[]. The leaves have a somewhat sour flavour[]. A spicy and somewhat salty taste[]. The leaves are a source of omega-3 fatty acids, though seed sources such as walnuts are magnitudes richer[]. The leaves can be dried for later use[]. They contain about 1.8% protein, 0.5% fat, 6.5% carbohydrate, 2.2% ash[]. Another analysis gives the following figures per 100g ZMB. 245 - 296 calories, 17.6 - 34.5g protein, 2.4 - 5.3g fat, 35.5 - 63.2g carbohydrate, 8.5 - 14.6g fibre, 15.9 - 24.7g ash, 898 - 2078mg calcium, 320 - 774mg phosphorus, 11.2 - 46.7mg iron, 55mg sodium, 505 - 3120mg potassium, 10560 - 20000ug B-carotene equivalent, 0.23 - 0.48mg thiamine, 1.12 - 1.6mg riboflavin, 5.58 - 6.72mg niacin and 168 - 333mg ascorbic acid[].

Seed - raw or cooked[, , ]. The seed can be ground into a powder and mixed with cereals for use in gruels, bread, pancakes etc[, ]. The seed is rather small and fiddly to utilize[]. In arid areas of Australia the plants grow quite large and can produce 10, 000 seeds per plant, a person can harvest several pounds of seed in a day. The seeding plants are uprooted and placed in a pile on sheets or something similar, in a few days the seeds are shed and can be collected from the sheet[]. In Britain, however, yields are likely to be very low, especially in cool or wet summers[]. The seed contains (per 100g ZMB) 21g protein, 18.9g fat 3.4g ash[]. Fatty acids of the seeds are 10.9% palmitic, 3.7% stearic, 1.3% behenic, 28.7% oleic, 38.9% linoleic and 9.9% linolenic[].

The ash of burnt plants is used as a salt substitute[].

Medicinal

Purslane has been used in folk medicine since ancient times and is included in the World Health Organization’s list of most widely used medicinal plants[].
Aqueous extracts of the plant have shown muscle-relaxing effects[].
Ethanolic extracts showed significant analgesic and anti-inflammatory effects[].
A crude extract of the plant has been shown to accelerate wound healing when applied topically[].
An ethanolic extract showed antifungal activity against Trichophyton dermatophytes[].
Extracts of the plant have shown antityrosinase activity and are being tested for their skin-whitening activity[].

The plant is anthelmintic, antibacterial, antiinflammatory, antiscorbutic, depurative, diuretic and febrifuge[, , , , ]. The leaves are a rich source of omega-3 fatty acids, which is thought to be important in preventing heart attacks and strengthening the immune system[]. Seed sources such as walnuts, however, are much richer sources[]. The fresh juice is used in the treatment of strangury, coughs, sores etc[, , , ]. The juice extracted from 1OOg of pounded fresh plant and diluted with water serves as an anthelminthic against oxyuriasis and ascariasis[]. A tea made from the leaves is used in the treatment of stomach aches and headaches[].
The leaves are poulticed and applied to burns[], both they and the plant juice are particularly effective in the treatment of skin diseases and insect stings[, ]. The leaf juice is applied to earaches, it is also said to alleviate caterpillar stings[].
The leaves can be harvested at any time before the plant flowers, they are used fresh or dried[].
This remedy is not given to pregnant women or to patients with digestive problems[].

The seeds are tonic and vermifuge[, ]. They are prescribed for dyspepsia and opacities of the cornea[].

Other Uses

None known

Propagation

Seed - for an early crop, the seed is best sown under protection in early spring and can then be planted out in late spring[]. Outdoor sowings in situ take place from late spring to late summer, successional sowings being made every two to three weeks if a constant supply of the leaves is required[].