One of my friends in the dorm has a cactus plant on his shelf, and given that I had been stabbed twice throughout the year by it, I decided to examine one of the spines to see what it looked like. I discovered that the structure looked remarkably similar to a human hair to me, with the exception that the interior of the spine reminded me of wood grains rather than the fractured look of a hair. Wanting to learn more about cactus spines in general, I did some research and discovered that my friend’s cactus was one with smooth spines, as opposed to the barbed spines that are also commonly found on various cacti species. In contrast to barbed spines, which have the primary purpose of being ripped out along with some of the cactus plant to be dropped and thus grow another cactus, smooth-spined cacti utilize their spines in an almost purely defensive manner, with secondary functions to draw water from the air or maintain the temperature of the plant.