Trivia: Cactus spines are a kind of what?
Thorn
Leaf
Stem
Flower
The correct answer is Leaf
So why is this answer correct? : Although cactus spines resemble thorns, these prickly structures are actually modified leaves that protect the plant from hungry herbivores while radiating heat from the plant’s stem during the day. Spines also collect water vapor from the atmosphere at night, which then drips down to the base of the plant.