A succulent is a plant characterized by thick, juicy flesh which is well suited to high water retention. The plants evolved in arid climates all over the world, and they vary widely in size and shape. Many people use succulents as ornamental plants, especially in low water gardening such as zeroscaping. The low water plants can look quite lovely, with some succulents producing stunning and unusual looking flowers.
Several traits are shared among all succulents. The first is very dense, thick stems, often protected by a spiny, hairy, or waxy surface. The fleshy stems of succulents may perform the bulk of photosynthesis for the plant, while the surface helps to keep the plant from drying out. Succulents also tend to grow in very compact ways, minimizing potential water loss and exposure to the sun. The plants may also adapt long roots to reach the water table.
The leaves of succulent plants are often considered one of their distinguishing features. A succulent either has few to no leaves, or very thick, dense leaves which tend to grow in clusters for protection. In the case of a succulent which has minimal leaves, the leaves are often small and fleshy, designed to use water as efficiently as possible as long as they are on the plant. Many succulents also produce useful compounds in their leaves, as is the case with aloe vera.
When a succulent has flowers, they often close during the day to protect themselves from the heat. In addition, the pores which plants use for gas exchange with their environment remain closed during the day, to prevent evaporation. At night when the temperature is cooler, the leaves and pores open. This prevents the plant from being damaged by intense heat, which can cause dryness and ultimate death.
Many succulents thrive in dry soils and poor conditions, because they are adapted to use their environment with maximum efficiency. This makes them a popular choice for beginning gardeners, since they can be very hard to kill. The unusual look of succulents is also a desirable trait for some gardeners. An entire garden can be planned with succulents, since the plants come in such a range of shapes, colors, and sizes. In dry climates where xeriscaping is highly recommended, succulents often form the backbone of a successful garden. In addition to using water efficiently themselves, the plants also tend to trap water and nutrients which can be used by neighboring plants.