This member of the Apocynaceae family was described by Henri Louis Poisson in 1922. It is found in central Madagascar, growing on bare rocks with some water and lots of sun. The caudex can grow to 40 centimetres in diameter, the stem up to three or even four meters. The flowers are white.
The genera name from Greek; pachys; 'thick' and Greek podion; 'small foot' for the thick caudiciform trunk, formed by some species. The species name after Raymond Decary, 20th century plant collector. Flower photo by Ferdinand Poilodan.

