Pelargonium is a genus of flowering plants which includes about 200 species of perennials, succulents, and shrubs, commonly known as geraniums or storksbills. Confusingly, Geranium is the correct botanical name of a separate genus of related plants often called Cranesbills. Both genera are in the Family Geraniaceae. Many of the South African species of Pelargoniums have succulent tissue in the stems, trunk, and/or roots. These shrubs stay relatively small, with a maximum height of about 2 feet (0.67 meters). These species are characterized by thick upright stems topped with delicate non-succulent leaves borne on green spikes that break off easily. During dry times, the green foliage will dry and fall off very quickly. However, when water returns, a seemingly dead plant springs back to life within 48 hours. Many gardeners grow Pelargoniums for their flowers. The flowers resemble orchid flowers and have almost as interesting range of shapes and colors. 

Here some photos representative of caudiciform Pelargoniums.

Pelargonium paniculatum

Pelargonium alternans

Pelargonium carnosum

Pelargonium echinatum

Pelargonium laxum

Pelargonium nana origin East Africa