Succulent very particular, in many respects similar to a cactus consisting of a columnar stem that develops in 4 or 6 deeply furrowed and angular angles. The epidermis of Euphorbia assumes a bluish color so peculiar and characteristic to confer the name to the species (in Latin literally "glaucous, bluish"). The edges of the ribs are pleasantly adorned by a whitish longitudinal line, along which emerge opposite pairs of robust and rather short spines on the notes of brownish, tending to gray in the mature plant. As it grows, the stem shows a pleasantly wavy trend, characterized by wider areas and narrower areas at times of greater or lesser growth of the succulent. In nature, E. caerulescens tends to branch abundantly from the main stem, giving rise to large thorny pillows of a decidedly unmistakable blue.