This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Annual. Propagates by seeds. Time of bloom: Late June until cut off by frost. Seed-time: July until killed by frost.
Range: Throughout North America except the northern part. Habitat: Cultivated ground, waste places.
The noted experiments with buried seeds, conducted by W. J. Beal, Botanist of the Michigan Agricultural Experiment Station, demonstrated that the seeds of Purslane will germinate after having lain dormant in the soil for thirty years. Few gardens are without the weed. It is said to harbor both the melon plant louse and the corn root louse; also it is sometimes attacked by a white mold, which may make it a menace to better plants.
Stems four inches to more than a foot in length, prostrate, thick, round, smooth, succulent, branching on all sides from the central root and again often forking. Leaves, alternate, obovate or wedge-shaped, with rounded tips, very small, thick, and fleshy, mostly clustered at the ends of the branches. Both stems and leaves often have a reddish tinge. Flowers solitary, sessile, about a quarter-inch broad, opening only in the brightest sunshine; sepals two, broad, pointed, keeled; four to six - mostly five - broadly rounded yellow petals, soon falling away; stamens seven to twelve; style five- or six-parted. Capsule urn-shaped, one-celled, membranous, many-seeded, opening transversely and the top falling off like a lid; when near maturity, the plants can hardly be touched without sowing these seeds by hundreds. The weed is most tenacious of life, often readjusting itself after having been torn up bodily, the fleshy stems, and leaves sustaining it while doing so, if not placed where the feat is impossible. (Fig. 103.)
Killing while in the seedling stage by constant shallow hoeing is the only way of vanquishing this weed. If old enough for seed-cones to begin to form, plants should be removed from the soil, for the stems and roots retain life enough to ripen and distribute seed. Pigs are very fond of Purslane, and one of those greedy animals will dispose of a considerable crop. Or the plants may be thrown on a compost heap, where fermentation will destroy the vitality of the seeds.
Fig. 103. - Purslane (Portulaca ole-racea). X 1/2.