Euphorbia is a genus in the family Euphorbiaceae. Consisting of 2008 species, Euphorbia is the fourth largest genus of flowering plants. Succulent species originate mostly from Africa, the Americas and Madagascar. The common name “spurge” derives from the Middle English/Old French espurge (“to purge”), due to the use of the plant’s sap as a medicinal purgative. The plants are annual or perennial herbs, woody shrubs or trees. Smaller Euphorbias make excellent potted plants while larger species are valuable landscaping plants.

Euphorbia coerulescens is indigenous to southwestern South Africa. It is a freely branching species with many stems rising from the ground. Each fat stem slowly grows to as much as 1.5m high, has four to six angles and is divided into many joints. It is rather similar to Euphorbia avasmontana, but does not grow quite as large, the stem segments are shorter, the crests of the ribs have a dark (as opposed to a light coloured) horny chitinous ridge bearing two-pronged 1.25cm long spines, and the colour of the stems is never bluish. It is nevertheless a beautiful species and looks very much like a cactus species.