Species in Pachypodium

The smallest species in the genus with a flattened, tuberous caudex 2-8cm tall and up to 40cm in diameter, resembling a rock or cluster of potatoes. Virtually branchless with sparse leaves in rosettes. Produces bright yellow trumpet-shaped flowers. Strictly adapted to acidic substrates with pH 3.5-4.5.

A caudiciform succulent with a swollen, balloon-shaped silvery-gray caudex up to 40cm in diameter. The plant reaches up to 90cm in height with slender reddish-brown branches bearing paired spines. Produces bright yellow, fragrant flowers on long peduncles. Leaves are narrow and deciduous during the dry season.

Pachypodium lamerei is a stem-succulent tree in the dogbane family (Apocynaceae), endemic to Madagascar. In the wild it reaches about 2 to 5 m, sometimes more, with a swollen, water-storing trunk covered in sharp spines up to 5 cm long arranged in groups of three. Long, narrow leaves cluster at the top of the stem and are shed in the dry season, while the stem keeps photosynthesizing by CAM (a water-saving pathway that takes up carbon dioxide at night). Mature plants, usually around 1.8 m or taller, bear clusters of white tubular flowers up to about 7 cm long. Damaged stems exude a milky sap that is considered toxic. All Pachypodium species are listed in CITES (the Convention on International Trade in Endangered Species), and this species is in Appendix II.