Origin and Habitat: Falaise de l'Ankarana and Mount Anjenabe in the northeast of Madagascar.
Altitude range: 600-800 metres above sea level.
Habitat and ecology: Cyphostemma pachypusSN|33422]]SN|33422]] grows on limestone in deciduous forests or on gneiss in shaded forests near the gorges often completely buried and wedged between rocks.

• Cyphostemma pachypus Desc.

Description: Cyphostemma pachypusSN|21898]]SN|33422]] has the same growth habit as Cyphostemma elephantopusSN|33422]]SN|21898]]. It is a weird but ornamental herbaceous perennial caudiciform vine, with a massive caudex that is either subterranean or grows between limestone rocks.
Caudex: Above-ground or completely buried and wedged between rocks, globular when young, flask-like in age with a tapering shape, this underground storage organ can attain surprisingly large dimensions 50-70 cm high, 40-50 cm in diameter. The bark is fissured, brown. The climbing vines are thin, succulent and reach about the height of two meters in cultivation (but in habitat they can reach the length of more than 6 metres)
Roots: Thick, fibrous.
Leaves: 3- to 5-pinnate. Leaflets elliptic or ovate-elliptic, apex acute.
Inflorescences: Corymbose cymes.

Bibliography: Major references and further lectures
1) Werner Rauh “Succulent and xerophytic plants of Madagascar”, Volume 1 Strawberry Press, 1995
2) Bernard Descoings “Cyphostemma (Vitacées) nouveaux de Madagascar”, Bulletin de la Société Botanique de France, 109:9, 266-276, (1962)

Cultivation and Propagation: Cyphostemma pachypusSN|33422]]SN|33422]] should make an interesting addition to a collection, buy is rare in cultivation.. It is suited to greenhouse culture, but does well outdoors in subtropical climates. It doesn't like a wet winter, but will survive.
Growth rate: It grows well, though very slowly, but it possible to increase the speed of growth to some extent by providing adequate amount of water, warmth, and fertilizer during the active growing season, but it’s susceptible to rotting if too wet.
Exposure: It needs Full sun to light shade, but the caudex should be in the shade, while the leaves prefer the sun. Avoid direct blasting sun in summer.
Soil: It needs a a rich, very well drained potting medium (add pumice, vulcanite, and perlite).
Waterings: It should be watered plentifully in Summer and kept drier in Winter. This species like all pachycaul succulent species of Cyphostemma, is sensitive to excess moisture, and should be kept on the dry side. It rot easily and do NOT like a lot of water when it has no leaves.
Frost tolerance: Due to its African origin keep warm in winter, the minimum safe average temperature is 12°C, although it can go lower for short periods. It can be grown outdoors in frost-free climates, need anyway to kept above 2°C and dry in winter. Can't stand any frost.
Maintenance: Repot every two years. It like pots with generous drain holes. Once this plant is established in its new pot, it should be cut back in height to encourage branching, to maintain an attractive shape and to ensure caudex habit. If pruned and kept somewhat pot bound, it can be maintained at a manageable size, depending on what ''manageable size'' means to you.
Propagation: The plants for decoration are grown from seed since they develop a perfect caudex. The seeds that must be prepared, aged and scarified, and even then germination is uncertain (cuttings are possible, but don't generally produce a caudex).