The desert ice plant, Mesembryanthemum crystallinum, is a fascinating succulent known for its shimmering appearance. Its leaves and stems are covered with unique, glistening structures that resemble ice crystals, giving the plant its common name and frosted look. This distinctive feature, along with remarkable biological adaptations, allows it to thrive in challenging environments.
Unique Appearance and Adaptations
The shimmering “ice” on the desert ice plant is not frozen water but specialized structures called epidermal bladder cells (EBCs). These enlarged cells, located on the plant’s surface, serve as reservoirs for water and excess salt, particularly sodium chloride. This adaptation classifies Mesembryanthemum crystallinum as a halophyte, a plant capable of growing in highly saline conditions. The EBCs help sequester ions, maintaining a balanced internal environment within the photosynthetically active tissues.
Beyond its salt-storage capabilities, the desert ice plant exhibits a physiological adaptation involving its photosynthetic pathway. Under normal conditions, it performs C3 photosynthesis. However, when subjected to environmental stresses like drought or high salinity, M. crystallinum can switch to Crassulacean acid metabolism (CAM). This shift allows the plant to open its stomata and absorb carbon dioxide primarily at night when cooler temperatures reduce water loss. The stored carbon dioxide is then used for photosynthesis during the day, significantly enhancing water use efficiency.
Native Habitat and Global Spread
The desert ice plant is indigenous to several arid and semi-arid regions across the globe. Its native range includes parts of Southern Africa, such as Namibia and South Africa, along with the Sinai Peninsula and areas of Southern Europe, including Italy, France, and Spain. This species naturally thrives in disturbed, saline coastal areas or desert soils. It can be found on various soil types, from sandy dunes to loamy and clay soils, as long as they are well-drained.
Over time, Mesembryanthemum crystallinum has become naturalized in many other parts of the world, often due to accidental or intentional introduction. Notable areas where it has spread include Australia and various regions of the Americas, particularly California. It is important to distinguish this plant from the invasive highway ice plant (Carpobrotus edulis), a common point of public confusion. While both are succulents often found in similar habitats, M. crystallinum has distinct crystalline bladder cells, whereas Carpobrotus edulis is characterized by larger, less crystalline leaves and different flower shapes and colors.
Cultivation in a Garden Setting
For home gardeners, the desert ice plant’s cultivation requirements are straightforward. The plant prefers well-draining soil, thriving in sandy or poor conditions. A cactus or succulent potting mix is often ideal to ensure proper drainage and prevent root rot. Once established, it has low water needs and should be watered sparingly, allowing the soil to dry out completely between applications.
Full sun exposure is preferred for growth. While it can be an annual, biennial, or perennial, it is often grown as a half-hardy annual in regions with frost, as it is not tolerant of freezing temperatures. Propagation is simple, as the plant can be started from seeds sown in spring or from cuttings. Young seedlings benefit from plenty of ventilation and dry growing conditions to prevent damping off.
Culinary and Other Uses
The desert ice plant has gained recognition as an edible green, frequently referred to as “ficoïde glaciale” in culinary circles. Its flavor profile is distinctly briny and salty, often likened to spinach with a fresh, crisp taste. The texture is a unique combination of crunchy and succulent, even after light cooking, due to the bursting epidermal bladder cells. It is often enjoyed raw in salads, where its refreshing salinity can enhance other ingredients, especially seafood.
The plant can also be lightly steamed or sautéed, retaining its appealing crunch. Beyond its culinary appeal, Mesembryanthemum crystallinum holds other potential applications. It has been studied for its role in phytoremediation, the process of using plants to remove or stabilize contaminants from soil. Its ability to accumulate and sequester salts makes it a candidate for reclaiming degraded or contaminated lands.