Portulaca oleracea

pigweed

 

Portulaca oleracea

L. 1753

pronounced: por-tew-LAK-uh awl-ur-RAY-see-eye

(Portulacaceae — the portulaca family)

 

common names: pigweed, portulaca

native 4Portulaca is the name the Romans gave to the purslane; it comes from portare, to carry, and lac, milk, referring to the milky sap. Oleracea is also Latin, from oleraceus, vegetable.
This grows as a weed in disturbed areas, cultivated areas and garden beds, usually after rain. It has an extensive Old World distribution, extending from North Africa through the Middle East and the Indian subcontinent, to Malesia and Australasia. Its status in the New World is uncertain, although it is thought to have reached North America before Columbus. It is now naturalized throughout much of the world, in cold climates as well as hot. In Australia it is found in all states except Tasmania.

Pigweed is an annual plant with a thickened taproot with fibrous secondary roots and smooth, reddish, fleshy stems that are mostly prostrate and grow up to about 25 cm along the ground. The alternate leaves are obovate to oblanceolate, clustered at stem joints and ends, and are up to 2.5 cm long. The yellow flowers have 5 regular parts and are up to about 6 mm wide.

Depending on rainfall, the flowers can appear at any time of the year. They open singly at the centre of the leaf cluster, for only a few hours on sunny mornings. The fruit is a tiny pod, that opens when the seeds are mature.
Its tiny black seeds are one of the most important bush foods of central Australia. The indigenous people pull up the plants and throw them in heaps. After a few days they turn the heaps over, when most of the seeds will have fallen out. The seeds contain up to 20% protein and 16% fat. The seed is processed by grinding on a flat rock with a hand-held stone, and the resulting flour is made into a damper.

Although in Australia and the USA the plant is usually considered a weed, it may be eaten as a leaf vegetable. It has a slightly sour and salty taste, and is eaten throughout much of Europe, the Middle East, Asia and Mexico. The leaves, stems and flower-buds are all edible, although the flavour is reckoned to be better if the leaves and stems are collected before the plant comes into flower. It may be eaten as a salad ingredient, or stir-fried, or cooked as spinach is, and because it is mucilaginous, it can be used in soups and stews. In Greece the leaves and stems are fried with feta cheese, tomato, onion, garlic, oregano and olive oil.

It has been used as a medicinal plant for centuries. Dioscorides in the 1st century AD described it as having medicinal powers. He wrote that it reduced the sex drive, could expel worms, and relieved the pain of headaches. Pliny the Elder, also writing in the 1st century, advised wearing the plant as an amulet to expel all evil. In Chinese traditional medicine it is known as Ma Chi Xian (horse-tooth amaranth). The plant contains a high amount of omega-3 fatty acids, vitamins A, B, C and E, potassium, calcium, magnesium and lithium, the last a natural antidepressant used to treat bipolar disorder. Most traditional medicine practitioners advise that pregnant women should not use this plant medicinally. The plant is also used in animal feed, where it is said to stimulate the animal’s immune system and to help prevent scouring.

The crushed leaves or the juice of the plant are sometimes applied directly to the skin to treat burns, insect stings, sores and acne.

The caterpillars of several Lepidoptera feed on the plant, including:

      • the Diadem Hypolimnas misippus;
      • the Beet Armyworm Spodoptera exigua;
      • the Cacao Armyworm Tiracola plagiata;
      • the Meadow Argus Junonia villida; and
      • the Australian Striped Hawkmoth Hyles livornicoides.

 
Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.

 

Photographs taken in a Picnic Bay garden 2014
Page last updated 18th March 2019