Thorn is a sharp-pointed
stem which has tiny
leaf scars and arises from a
modificated
axillary or
apical
bud whereas spines usually develop from the
leaves. Because of this, breaking a
thorn off the plant damages the surrounding
tissue.
Thorns are hard while spines are comparatively soft. It’s main function
is the protection from the enemies.
Prickles and spines are technically different from thorns, but have
the same overall effect.
