Common Purslane

Purslane grows from a taproot with fibrous secondary roots. The plant may reach 40 centimetres (16 inches) in height. It has smooth, reddish, mostly prostrate stems, and the leaves, which may be alternate or opposite, are clustered at stem joints and ends. The yellow flowers have five regular parts and are up to 6 millimetres (1⁄4 inch) wide. Depending upon rainfall, the flowers appear at any time during the year. The flowers open singly at the center of the leaf cluster for only a few hours on sunny mornings. The tiny seeds are formed in a pod that opens when the seeds mature. The fruits are many-seeded capsules. The seed set is considerable; large plants have been reported to produce up to 240,000 seeds. The seeds germinate optimally at a temperature above 25 °C (77 °F); they are light germinators, with even a soil cover of 5 mm having a negative effect on germination. Although usually an annual plant, it is a tropical perennial in United States Department of Agriculture growing zone 11.

Metabolism. P. oleracea is one of the very few plants able to utilize both C4 and crassulacean acid metabolism (CAM) photosynthesis pathways, long believed to be incompatible with each other despite biochemical similarities. P. …

Purslane has an extensive distribution, assumed to be mostly anthropogenic (or hemerochoric), extending from North Africa and Southern Europe through the Middle East and the Indian subcontinent to Malesia and Australasia. The species status in the Americas is uncertain. In general, it is often considered an exotic weed, but there is evidence that the species was in Crawford Lake deposits (Ontario) in 1350–1539, suggesting that it reached North America in the pre-Columbian era. Scientists suggested that the plant was already eaten by Native Americans, who spread its seeds. How it reached the Americas is currently unknown.

The taproot helps the plant tolerate poor soil and drought. Compared to other common crops, P. oleracea is more tolerant of pests due to its waxy cover, which protects the plant from insects and diseases. In some instances, P. oleracea is even known to have antifungal properties. However some phytotoxic metabolites of Drechslera indica, a fungus, can cause necrosis on purslane. Dichotomophthora portulacae, another fungus, can cause stem rot. P. oleracea is a known host plant of Hyles lineata. Schizocerella pilicornis and Hypurus bertrandi are known to feed on Portulaca oleracea. In some instances, they may help control the competitiveness of P. oleracea to prevent weed infestation in fields where P. oleracea is not wanted, however, they do not stop it from growing completely.

Soil salinity. Salination of agricultural soils decreases the yields of many crops, and salt-sensitive species can no longer be cultivated on such soils. Purslane has a high tolerance for salt, making it suitable for cropping in areas where irrigation is carried out with water with high chloride-based salinity. Purslane can remove salt from the cultivation medium under saline conditions. As an intercrop or during one growing season, it can remove 210 kg/ha of chloride and 65 kg/ha of sodium when cultivated at 6.5 dS/m, allowing growth of salt-sensitive plants on saline soils. …

Raw purslane is 93% water, 3% carbohydrates, 2% protein, and contains negligible fat. In a 100-gram reference amount, purslane supplies 20 calories, and rich amounts (20% or more of the Daily Value, DV) of vitamin E (81% DV) and vitamin C (25% DV), with moderate content (11–19% DV) of several dietary minerals. Purslane is a source of alpha-linolenic acid, an essential omega-3 fatty acid. Purslane leaves are very high in oxalates, containing high levels, with one study finding \(23.45\pm 0.45\) g total oxalates per kg of fresh weight (or 23450 mg/kg). Another source reports \(671-869\) mg/100g fresh weight.

The specific epithet oleracea means "vegetable/herbal" in Latin and is a form of holeraceus (oleraceus), from holus 'vegetable'. The genus name portulāca is simply the plant's name in Latin.