Portulaca oleracea L.
This species grows best in full sun and can tolerate poor soil conditions and moderate drought. Common purslane is often found in poorly maintained, thinning turf, and in newly established turf seeded in late spring or summer. Newly emerged plants are usually upright but tend to lie flat against the soil surface and spread outward from central growing points in roughly radial patterns. Common purslane is most noticeable during warm summer months.
Common purslane is a member of the Portulaca family and has a summer annual life cycle. Plants emerge from seeds from late spring to midsummer, produce taproots from central growing points, and spread laterally in radial patterns, but do not root at nodes. This species produces small yellow flowers during mid to late summer. Seeds remain dormant over the winter months then germinate and give rise to new plants in spring and summer of the following year.
Stems of common purslane are red or pink, with a smooth surface (no hairs), and lie close to the ground. Leaves are relatively thick and succulent, oblong or wedge-shaped, and up to 1.5 inches long. Leaf margins are smooth, rounded at tips, and taper to a point at the base. Leaves typically do not have petioles and are arranged opposite one another in clusters on stems. Common purslane produces very small yellow flowers (1/4 to 1/3-inch diameter) with five notched petals. Flowers are formed in leaf axils and open only in full sun. Seeds are produced in capsules that split when mature and drop seed onto the soil surface.
Infestations of common purslane in newly planted lawns can be reduced by establishing turf in late summer or fall. In established lawns, common purslane populations can be reduced by improving turf density through fertilization, regular mowing, and the use of turfgrasses well-adapted to site conditions. This weed can be controlled with various postemergence herbicides, particularly products containing two or more of the following active ingredients: 2,4-D, dicamba, MCPA, MCPP, triclopyr, or fluroxypyr. Some preemergence herbicides will control common purslane from seed but have no effect on emerged plants.