Be careful, this rose has thorns and will prick you.
Tips
history
朿 'thorn' is archaic and not used independently in modern Chinese. It survives as the phonetic in 刺 (to stab / a thorn), 策 (plan / whip), and doubled in 棘 (brambles, two thorn-trees side by side).
memory
Picture a bare tree 木 with a sharp point added on top: that spike is exactly what 朿 draws.
Components
pictograph
朿cì
thorn
A picture of a tree 木 topped by a sharp spike — the thorn itself. Treated as one pictograph since the spike and tree are drawn as a single unit.
Filed under radical 木 (mù, #75) by convention. 木 is not a separate component in 朿, so no strokes are highlighted.