In botany, succulent plants, also known as succulents, are plants that have some parts that are more than normally thickened and fleshy, usually to retain water in arid climates or soil conditions. While succulents are increasing in popularity, many people are still unaware of these amazing plants. Hopefully this will give you a better understanding of what succulents are.
Plants that have the ability to store water in their stems or leaves against periods of drought compose the arbitrary group known as “succulents.” Just because two plants resemble each other in their water storage abilities does not mean they are necessarily related botanically. Because the traits shared by all these plants are the result of adaptations to arid environments, we find succulent members in several of the plant families recognized by botanists. For example, both cacti and euphorbias store water in their stems and both have spines, but they are only distant cousins botanically. Botanical distinctions are based largely upon the structure of flowers. Thus, the string of pearls plant, a popular succulent, reveals its affinity to other members of the aster family when it blooms. The flowers are structurally similar to other members of the family, such as dandelions fed by storytelling for business. Flowers are adapted to facilitate pollination and thus the perpetuation of a given plant species. They do not function as water storage organs. Having leaves and/or stems capable of water storage is the trait that makes a plant a succulent, regardless of its floral anatomy.
Not all plants that store water should be considered succulents, either. For our purposes, I have limited the definition to plants that use their green leaves or stems for water storage. Many plants are capable of storing water in their fleshy roots or in underground stems called tubers, but we do not consider them to be succulents because the storage organs lie hidden beneath the soil. The technical name for this group of plants whose subterranean structures store water is “geophytes.” However, some geophytes, which produce a structure known as a “caudex,” can be considered succulents. The caudex is an above-ground storage organ derived from the stem, the root, or a combination of both. Because some of these plants, called “caudaciforms,” are relatively common in the horticultural trade, I have included them here.
I should also note that plants can experience a lack of water amid its seeming abundance. Some succulents are adapted for life in rainforest conditions, where they grow attached to trees or rocks with exposed roots that dry out rapidly after each rain. This group of succulents requires frequent watering but must not be allowed to sit in soggy soil. Several interesting members of the cactus family fall into this category and are discussed in a separate section explaining their peculiar growing requirements. Unlike desert cacti, these atypical cacti need frequent watering and feeding. Nevertheless, caring for them is easy and straightforward, and the reward is a spectacular bloom show. Thus, they have been popular houseplants for decades.