A storage organ is a part of a plant specifically modified for storage of energy
(generally in the form of carbohydrates) or water. Storage organs often grow underground, where they are better protected from attack by herbivores. Plants that have an underground storage organ are called geophytes in the Raunkiær plant life-form classification system. Storage organs often, but not always, act as perennating organs which enable plants to survive adverse conditions.
A harvested ginger rhizome
Crassula arborescens, a leaf succulent
Ferocactus pilosus (Mexican lime cactus), a stem succulent
In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word succulent comes from the Latin word sucus, meaning "juice" or "sap".
Succulent plants have thickened stems, or leaves, such as this Aloe.
The center rosette of (Aloe polyphylla)
A collection of succulent plants, including cacti, from the Jardin botanique d'Èze, France
Succulents, such as these Adromischus marianae, Crassula deceptor and Conophytum, share an affinity for arid, fast-draining soils, often growing directly on rocks