You’ve probably noticed that certain plants, like roses and cacti, have prickly thorns that hurt you if you accidentally touch them! – Ouch! Why do these plants need these scratchy spikes?
The answer depends a little bit on which plant you’re talking about. When it comes to roses, the thorns are mostly there for defense – an animal won’t eat a rose bush if it’s going to get all scratched up during the meal!
Cacti also have their spikes for this same reason, but also for another important reason: The thorns on a cactus are like their replacement for leaves! This helps them to lose less water in the desert heat. And, for cacti with enough spines, they also sometimes help to provide the plant with some shade!