Portulaca oleracea is an annual C4 herb (Downton 1971), from a thick taproot with a dense mat of secondary roots; stem prostrate, reddish; mat-forming, succulent.
Leaves alternate to subopposite, succulent, to 2.8×1.3 cm, paddle-shaped, widest above middle, tip rounded.
Flowers yellow, ca 0.7 cm, petals shorter than sepals, sessile, in small axillary or terminal clusters, self-fertile (autogamous), (Mulligan and Kevan 1973).
Fruit a rounded capsule, to 0.9 cm long, tip pointed, appearing similar to flower bud when unripe; seeds numerous, dark (Flora of North America 1993+); seeds eaten by birds and small mammals, plants eaten by small mammals (Martin et al. 1951); edible when young. Seeds are dropped under parent plant, require temperatures above 30º Celsius to germinate. Seedling emerge from late May to August, seeds are set in 2-4 months. Long days (16 h) stimulate vegetative growth, short days (12 h) stimulate reproduction. Seeds can ripen on senescent plants after frost.
Wetland status: FAC.
Frequency in NYC: Occasional.
Origin: Possibly S. Asia, but disputed, possibly S. America or Africa, but seeds have been found in pre-Columbian sediments in N. America (Byrne and McAndrews 1975; Miyanishi and Cavers 1980).
Habitat: An agricultural weed, common in high nutrient, open soil, gardens, new fill, roadsides, vacant lots, curbs, sidewalks. Drought tolerant, intolerant of shade, intolerant of sterile soil, soil pH 5.6-7.8.
Notes: Edible raw or cooked and apparently highly nutritious (Wikipedia contributors. 2006 +; Flora of North America 1993+). Purslane is a host for the sugar beet nematode and a leafminer, the larvae of the sawfly Sofus pilicornis. Also host to the white rust fungus Albugo portulacae and to Helminthosporium portulacae (Miyanishi and Cavers 1980).