The specifies commemorates Baron Milius, once Governor of Réunion, who introduced the species to France in 1821.

[3] The native Malagasy name for this plant, songosongo, has also been applied to several other Euphorbia species.

E. milii is a woody, succulent subshrub or shrub growing up to 1.8 m (5 ft 11 in) tall, depending on cultivar, with densely spiny stems.

The flowers are small, subtended by a pair of conspicuous petal-like bracts, variably red, pink or white, up to 12 mm (0.47 in) broad.

The World Health Organization (WHO) has recommended the usage of Euphorbia milii in aiding snail control.

E. splendens) is considered to be the living embodiment of the supreme deity in Bathouism, a minority religion practiced by the Bodo people of Eastern India and Nepal.

[14] Wat Phrik in Thailand claims to be the home of the world's tallest Christ thorn plant.