[citation needed] 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.

[8] Due to the great variability, a large number of subspecies and varieties have been described as species of their own, but according to other publications, they all fall within the range of variation of P. oleracea.

[2] Purslane has an extensive distribution, assumed to be mostly anthropogenic (or hemerochoric),[13] extending from North Africa and Southern Europe through the Middle East and the Indian subcontinent to Malesia and Australasia.

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.

[14] 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.

[26] It has a slightly sour and salty taste and is eaten throughout much of Europe, North Africa, the Middle East, Asia, and Mexico.

Greeks, who call it andrákla (αντράκλα) or glistrída (γλιστρίδα), use the leaves and the stems with feta cheese, tomato, onion, garlic, oregano, and olive oil.

In Turkey, besides being used in salads and baked pastries, it is cooked as a vegetable similar to spinach or is mixed with yogurt to form a tzatziki variant.

In the Alentejo region of Portugal, purslane is used for cooking a traditional soup (sopa de beldroegas) which is topped with soaked bread, poached eggs, and/or goats' cheese.

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−1, allowing growth of salt-sensitive plants on saline soils.

In the 4th century BC, Theophrastus names purslane, andrákhne (ἀνδράχνη), as one of the several summer pot herbs that must be sown in April (Enquiry into Plants 7.1.2).

[36] As Portulaca it figures in the long list of comestibles enjoyed by the Milanese given by Bonvesin de la Riva in his "Marvels of Milan" (1288).

[37] In antiquity, its healing properties were thought so reliable that Pliny the Elder advised wearing the plant as an amulet to expel all evil (Natural History 20.210).

[42] Verdolaga, the Spanish word for purslane, is a nickname for South American football clubs with green-white schemes in their uniforms, including Colombia's Atletico Nacional and Argentina's Ferrocarril Oeste.