Uncarina

Uncarina is a genus of semi-succulent flowering plants in the Pedaliaceae (the sesame family) found in Madagascar. As most species within the genus are inhabitants of dry, semi-arid or seasonally-dry regions, many mature into water-storing pachycauls, or "caudiciformes"—a common colloquial term to describe plants that normally inhabit drier climates and develop a large, woody base, or "foot", known as a caudex. In these species, a plant's lower half gradually accumulates and stores water (similarly to a camel's hump); over time, the caudex changes shape, swelling to an often impressive size, as it adds to its own moisture "reservoir" for future periods of drought. In addition to Uncarina, many other caudex-forming genera can be found on Madagascar as well as beyond, such as Adenium, Beaucarnea, Dioscorea, Euphorbia, Gerrardanthus, Pachypodium and Stephania, among others....read more on Wikipedia.