Euphorbia resinifera

Euphorbia resinifera (Resin spurge) is a species of spurge native to Morocco, where it occurs on the slopes of the Atlas Mountains.

It is a shrub growing to 60 cm tall, forming multi-stemmed cushion-shaped clumps up to 2 m wide. The stems are erect, succulent, superficially like a cactus (an example of convergent evolution in a similar semi-desert climate), four-angled, with short but sharp pairs of 6 mm spines on the angles, spaced about 1 cm apart up the stem.

It is similar to its relative Euphorbia echinus, which occurs on the Moroccan coast and the Canary Islands.

It contains a high concentration of resiniferatoxin and is being used to develop a novel and powerful class of analgesics.