This member of the Asclepiadaceae family was given this name by Ulrich Meve and in Sigrid Liede shortly after John Jacob Lavranos and Bruno A. Mies named it Pseudolithos mccoyi. DNA however showed it were separate from the Pseudolithos genus. It is found in Oman and Yemen, growing in a real well drained soil with little to some water and lots of sun. The swollen stem can grow to two centimetres in diameter, the entire plant to seven centimetres in height - larger if it is grafted. The flowers are brown. The genera name from Latin, meaning 'deviating'. The species is named after the collector of the type-specimen; Tom McCoy. It has been known since A.G. Miller found one in the 1980's. I am actually not sure I would classify this as a caudiciform after all.