Euphorbia aeruginosa

About Euphorbia aeruginosa

The epithet aeruginosa means «verdigris-coloured», the blue-green of oxidised copper, and it describes exactly what you see: slender stems of a metallic blue-green with sharp ribs, and on them bronze-gold spines that stand out as though they were made of metal.

It is a small plant. The stems never exceed a centimetre across and the whole clump stays at 20-30 cm, so this is a table plant, one to look at close up. It grows slowly and branches from the base into a tight group.

It comes from northern South Africa, from Limpopo province, where it grows among quartzite rocks in full sun. It is one of the most sought-after succulent euphorbias precisely because of that colour, which looks like nothing else in the genus.

Botanical fact sheet

Care

Without direct sun it loses the blue. The metallic tone is a response to strong light: indoors or in part shade the stems turn ordinary green and the spines lose their golden shine. Of everything on this list, this is the plant that punishes poor light hardest.

Water very carefully: it is small, it has little root and it rots easily. Let the substrate dry out completely, and in winter keep it bone dry. It does not take cold as well as other euphorbias: below 8 °C, bring it under cover.

Did you know?

It is known as the miniature saguaro for the resemblance in habit to the great cactus of Arizona, but the likeness stops there: the saguaro is an American cactus and this is an African euphorbia. One more case of two unrelated plants arriving at the same shape by living in the same kind of place.