It is native to the Bismarck Archipelago, New Guinea, Wallacea and Southeast Asia.

Woody thin-walled capsules are slightly lobed, glabrous (hairless) and either smooth or spiny.

There are usually 2-3 seeds per fruit, obovoid (rounded at both ends), and slightly triangular in cross/transverse section.

The genus is distinguished from other Malesian Euphorbiaceae by the following traits:[5] if present the latex is not obvious; hairs are present; pistillate (female) flowers have apically split stigmas; the male (staminate) flowers have stamens that split into two equal branches, arising from 4‒7 androphores/stalks, with ultimately more than 100 stamens.

He first described Spathiostemon as a genus in 1826 in the journal Bijdragen tot de Flora van Nederlandsch Indie.