– Pachypodium densiflorum (2008)

By Rhonda Smith (July 2008)

The generic name pachypodium is derived from the Greek words “pachy,” which means thick, and “podus,” which means foot. It refers to the characteristic thickened or swollen base of the plants’ stems, which are often partially underground.

Pachypodiums are caudiciform succulents, and many of the species produce spectacular flowers. They also exhibit a wide range of bizarre growth forms, from short, square and squatty to tall bottle- or candelabrum-shaped trees. Sizes range from a few centimeters above the soil to heights of more than 8 meters.

The Pachypodium genus was established by Lindley in 1830, at the time on the basis of a single species. Today Pachypodium consists of about 20 species. Five are native to continental Africa and the rest to Madagascar.

Pachypodiums are characteristically plants of hotter, drier regions of southern Africa and Madagascar, where they reach maximum diversity in terms of numbers of species.

However, the habitats of pachypodiums in Madagascar are disappearing fast as a result of human impacts. Urbanization and agriculture cause the decline of habitats and distribution ranges of many species, putting the smaller, slow-growing species especially at risk.

Pachypodium densiflorum occurs in central Madagascar. This is an extremely attractive plant, even when not in flower. The deciduous leaves are a medium green with a lighter middle vein and symmetrical veination. The trunk is a smooth silver with a light green tint. The spines are conical.

This species has yellow flowers that look very velvety, almost like butter. Flowers will set in the second year in good conditions.

P. densiflorum should be given full light and plenty of water during the warmer months and considerably less water in the cool months. The pachypodiums become dry during the dry season but will become spongy and then solid within a few days when they take up water.

They can survive extreme temperatures, but all species are sensitive to cold. The smaller species are suited to a warm greenhouse or sunny window sill, and can even be grown as bonsais. Pachypodiums also make ideal container subjects.

Owing to CITES restrictions, mass exportation of pachypodiums from the wild is prohibited. They are mainly cultivated from seeds, which germinate and establish easily. Propagation is also mainly from seed. Seedlings grow fairly slowly.

The attractive flowers of pachypodiums and the intriguing shapes of their swollen stems make them desirable for any garden. They are definitely not suitable for cold or damp gardens and are very sensitive to frost. If planted in a warm garden that experiences occasional frost, they should be given a warm, sheltered position.

Pachypodiums make good accent plants in rock gardens, especially when grouped together with other caudiciform succulent plants such as species of Adenia, Adenium, Pelargonium, Cissus and Cotyledon. All need full sun, lots of water (except during the dormant phase) and good drainage.

Be on the lookout for these beauties during the show. You will be hooked.