Not all purslane ( Portulaca oleracea ) is equal: varietal differences under greenhouse conditions

Purslane ( Portulaca oleracea L.) is a cosmopolitan annual herb with succulent foliage, widely consumed raw, cooked or pickled, and distinguished by its high α-linolenic acid (ALA) content, higher than that of common leafy greens. Purslane also provides linoleic acid (LA), diverse minerals, as well as vitamins A, C and E, underscoring its nutritional potential. Although cultivated commercially in parts of Asia, Europe and Mexico, purslane is often treated as a weed among conventional farmers. In temperate and cold climates, greenhouse production of purslane is essential to ensure year-round supply, yet research on promising varieties has been limited. We evaluated five commercially available purslane varieties (‘Red Gruner Microgreen Seed’, ‘Green Purslane’, ‘Scarlet’, ‘French Green Leaf’ and ‘Heirloom Verdolaga’) for growth, biomass and fatty acid profiles under greenhouse conditions. In addition to dry biomass, we measured plant height and diameter, which were integrated into a z-score growth index to assess temporal growth dynamics. The fatty acid profile of each variety was quantified using the Folch method. Biomass differed among varieties. ‘Green Purslane’ produced the highest yield (0.68 g plant −1 ), exceeding ‘Scarlet,’ ‘Heirloom Verdolaga’ and ‘Red Gruner,’ while ‘French Green’ showed intermediate yield. Growth trajectories were fastest for ‘French Green’ and ‘Red Gruner’. Although statistical analysis of this parameter was not performed, fatty acid composition of ‘Green’ showed a trend towards superiority, with 421 mg kg −1 LA, an exceptional 1625 mg kg −1 ALA, the lowest LA/ALA ratio of 0.26, and the highest polyunsaturated fatty acid proportion (73%), exceeding published ranges. We identified ‘Green’ as a strong candidate for indoor purslane production. Significance of the study What is already known on this subject? Our study addressed the research gap of purslane variety trials in greenhouse conditions. The availability of commercially bred purslane varieties is scarce; and the majority of existing studies that discuss purslane varieties either has an ethnobotanical background or deals with management or growth environments, such as saline conditions, while variety comparisons are only a secondary aspect. What are the new findings? Our study was limited to one single production cycle and by the small number of commercially grown purslane varieties accessible in the US which led to only five examined cultivars, which we examined regarding their yield. The fatty acid composition of each cultivar was measured from a composite sample. Based on this input, we identified the variety ‘Green’ as a promising material for indoor production, due to a satisfactory yield and a promising fatty acid profile by trend. What are the expected impacts on horticulture? The latter is relevant as health motivations, specifically omega-3 fatty acid content, may be central for a potentially growing customer base of the nutritious and tasty leafy green, which, in turn, could increase the number of commercial producers. Research comparing different seeding densities, fertilization managements, and light and watering regimes, and their impact on different purslane varieties could further improve purslane variety development and overall commercial production.