Learn the single most important difference—areoles—to avoid misidentifying Euphorbia as cactus.
Areoles = cactus
Cacti (e.g., Mammillaria spinosissima) have discrete areoles where spines and flowers emerge. Euphorbias (e.g., Euphorbia trigona) lack areoles and exude milky latex when cut.
Ribs & forms
Cacti show ribs/tubercles with areoles on each ridge; Euphorbias often have angled stems with paired spines at the edges.
Safety note
Wear gloves when handling Euphorbia latex; avoid contact with eyes/skin. Sterilize tools after trimming.
