Botanical names: Pseudolithos migiurtinus, Pseudolithos sphaericus
Common name: Pseudolithos
Family: Apocynaceae (Formerly:Asclepiadaceae)
Subfamily: Asclepiadoideae
Origin: Somalia
Pseudolithos migiurtinus is one of the rarest of the succulent milkweeds. Fleshy, hemispherical, often elliptical in section, pale green or yellow-green to grey stems 12 cm in diameter. The flowers are dark red and about 5/7 mm across.
It needs regular watering, especially during the hottest summer days; provide also some light watering if the green house temperatures in winter are elevated. Either excessive or very scarce watering can induce rot.
Link to this plant:
https://toptropicals.com/catalog/uid/pseudolithos_migiurtinus.htm