About Euphorbia trigona Mill.
Euphorbia trigona Mill. is an upright succulent shrub with many upward-growing branches. Its stem and branches may have two or three sides. The dark green stem features V-shaped light green patterns. Pairs of 5 mm (1⁄4 in) thorns grow along the stem’s ridges, and teardrop-shaped leaves emerge from between the two thorns on each ridge. This species has never been recorded to flower, and it is possibly a hybrid. In cultivation, Euphorbia trigona tolerates brief cold temperatures as low as −3 °C (27 °F). It prefers sandy soil, but can grow well in most well-drained soil types. It roots easily from stem cuttings: the cut stem must be left to dry for 3–7 days before planting to form a callus and prevent rot. Mature plants reach a height of 1.5–3 m (4 ft 11 in – 9 ft 10 in). Euphorbia trigona is only known to exist in human cultivation. It is widely grown as a houseplant, and in Gabon it is used as a ritual plant and for hedges.
