What has short stiff hairs or spines?

Many plants have short stiff hairs or spines, including cacti and various species of thistles. These structures often serve as a defense mechanism against herbivores, deterring animals from feeding on them. Additionally, they can help reduce water loss by minimizing air flow around the plant's surface. Examples include the spines of a prickly pear cactus and the hairy leaves of certain alpine plants.