Pachypodium is a genus of caudiciform succulents placed in the Apocynaceae family. Many of the species produce spectacular flowers. They exhibit a wide range of bizarre growth forms, from bottle-, cigar- or candelabrum-shaped trees to dwarf plants with very short stalks. Sizes range from a few centimetres above the soil to heights of more than 8 m. In southern Africa, the mystical elephant’s trunk or halfmens (Pachypodium namaquanum) is probably the best known and rarest member of the genus. Pachypodium is closely related to Adenium but distinguished from it in that the stipules at the base of the leaves are developed into long rigid spines. Pachypodiums are characteristically plants of hotter, drier regions of southern Africa and Madagascar where they reach maximum diversity in terms of numbers of species. Most species grow well in pots and rockeries. Larger species like Pachypodium geayi and Pachypodium lamerei make excellent landscaping plants too.

Pachypodium geayi is a tree of up to 8 m with a thick trunk that branches from a height of ± 3 m or more. Compared to Pachypodium lamerei, it has longer and thinner leaves at the tips of branches and the leaves and spines are covered in a velvet-grey hairiness. The white flowers are borne on much-branched inflorescences. The plants grow in dry woodland on calcareous and schist soils. It is more local and narrower in tolerance than Pachypodium lamerei, and in cultivation it seems to be more delicate. The epithet commemorates M. Geay who discovered the species. It grows in sand in low dry forest at altitudes from 0-100 m.