Carpobrotus edulis

C. edulis contains rutin, neohesperidin, hyperoside, catechin and ferulic acid; these contribute to the antibacterial[9] properties of the plant. It also contains procyanidins and propelargonidins.[10]

Carpobrotus edulis has naturalised in many other regions throughout the world, and is an invasive species in several parts, notably Australia, California and the Mediterranean, all of which have similar climates. The ice plant has escaped from cultivation and has become invasive, posing a serious ecological problem by forming vast monospecific zones, lowering biodiversity, and competing directly with several threatened or endangered plant species for nutrients, water, light, and space.[11]

Found at Cape Angela in Bizerte, Tunisia, near the Mediterranean Sea

Recorded as a garden escape from County Down,[12] in the south and east[13] and on the cliffs of Howth Head, County Dublin.[14]

On the Mediterranean coast, Carpobrotus has spread out rapidly and now parts of the coastline are completely covered. Moreover, another invasive species, the black rat, has been shown to enhance the spreading of the ice plant through its feces.[15] As the ice plant represents a food resource for the rat, both benefit from each other which is referred to as invasive mutualism.

Example of an area completely covered with ice plant on a French Mediterranean island, Bagaud island, in the Port-Cros National Park

In New Zealand forms monocultures and has taken over vast areas of coastal sand dune ecosystem. C. edulis and its hybrids are classed as unwanted organisms and are listed on the National Pest Plant Accord.[16]

The ice plant forms large monospecific zones.

Although the ice plant may have arrived by ship as early as the 16th century,[17][18] C. edulis was actively introduced in the early 1900s to stabilize dunes[17] and soil along railroad tracks; it was later put to use by Caltrans for ground cover along freeway embankments.[17] Thousands of acres were planted in California until the 1970s. It easily spreads by seed (hundreds per fruit) and from segmentation (any shoot segment can produce roots). Its succulent foliage, bright yellow flowers, and resistance to some harsh coastal climatic conditions (salt) have also made it a favored garden plant. The ice plant was, for several decades, widely promoted as an ornamental plant, and it is still available at some nurseries. Ice plant foliage can turn a vibrant red to yellow in color. Despite its use as a soil stabilizer, it actually exacerbates and speeds up coastal erosion. It holds great masses of water in its leaves, and its roots are very shallow. In the rainy season, the added weight on unstable sandstone slopes and dunes increases the chances of slope collapse and landslides.

The ice plant is still abundant along highways, beaches, on military bases, and in other public and private landscapes. It spreads beyond landscape plantings and has invaded foredune, dune scrub, coastal bluff scrub, coastal prairie, and, most recently, maritime chaparral communities. In California, the ice plant is found in coastal habitats from north of Eureka, south at least as far as Rosarito in Baja California. It is intolerant of frost, and is not found far inland or at elevations greater than about 500 ft (150 m).

Flowering occurs almost year-round, beginning in February in southern California and continuing until the autumn in northern California, with flowers present for at least a few months in any given population.

Control of ice plants can be attempted by pulling out individual plants by hand, or with the use of earth-moving machinery such as a skid-steer or tractor, though it is necessary to remove buried stems, and mulch the soil to prevent re-establishment. For chemical control, glyphosate herbicides are used. Because of the high water content of shoot tissues, burning of live or dead plants is not a useful method of control or disposal.