Sesuvium, or Shoreline Purslane, is one of those plants that is somehow introduced into a country, adapts quickly and is then seen everywhere. A sprawling, perennial herb, native on four continents, it has been seen increasingly in Arriyadh over the past ten years, and has become one of the toughest groundcovers there. Prostrate, up to 30 cm high, its stems extend up to 1 metre long, with smooth, fleshy, glossy-green, lanceolate leaves. With its many branches, rooting at the nodes, one plant will form a mat up to 2 metres in diameter. The small, pink flowers have green sepals on the outside and are pink on the inside. They flower all year round; the fruit is an inconspicuous capsule. Very fast growing, they thrive on wet to moist, saline and nutrient-poor soils, with or without humus; saltwater tolerance is extremely high. Drought tolerance is equally high and, once established, the plants require virtually no irrigation, although watering once or twice during the hot summer will result in better ground coverage and appearance. S. portulacastrum needs full sun and is relatively frost-tolerant in Arriyadh. It is easily propagated by cuttings and seed. Pests and diseases have not been reported. With its spreading mat of greenery, S. portulacastrum is something of a lawn substitute, providing instant green cover, especially good for roadside planting and medians. It is also an important sand stabilizer. Generally maintenance is very low, but plants are not very resistant to trampling, so that weeding a large area is difficult.