Portulaca oleracea (Purslane)

Description

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[5] are formed in a pod that opens when the seeds mature. Purslane has a taproot with fibrous secondary roots and can tolerate poor soil and drought.

The fruits are many-seeded capsules. The seed set is considerable; one plant can develop up to 193,000 seeds. The seeds germinate optimally at a temperature above 25 °C; they are light germinators, with even a soil cover of 5 mm having a negative effect on germination.

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 pathways despite biochemical similarities. P. oleracea will switch from C4 to CAM pathways during drought, and there is transcription regulation and physiological evidence for C4-CAM hybrid photosynthesis during mild drought.

Nutrition

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 rich source of alpha-linolenic acid, an essential omega-3 fatty acid.