Cactus spines. Coloured scanning electron micrograph (SEM) of glochids (thin sharp spines) on the surface of a bunny ears cactus (Opuntia microdasys). These glochids protect the plant from herbivores. They are easily loosened from the plant and some are barbed, making them difficult to remove from flesh. The glochids act as irritants, causing severe itching if touched and digestive disorders if eaten. They may even be loosened by strong winds, and can cause blindness if blown into the eyes. This cactus originated in northern Mexico, but is now grown worldwide as a decorative plant. Magnification: x15 at 6x7cm size. x26 at 4x5"~LANDSCAPE"