Euphorbia polyacantha is native to the mountainous regions of Kenya and Tanzania, favoring rocky slopes with well-drained volcanic soils. It is a polycarpic species with a bushy growth habit and features multiple spines along its branches, distinguishing it within the Euphorbia genus. Cylindrical segmented stems 1-2 cm diameter, bearing 4-7 spines per segment measuring 1-3 cm, arranged alternately. Green-gray coloration shifting to bluish tones during colder months.
Full direct sunlight exposure; irrigation reduced from October to March; substrate containing at least 70% volcanic mineral material. Minimum temperature 8 °C; prone to root rot if waterlogged.