Ouch! Thorns, Spines & Prickles

Many plants grow sharp prickles, spines or thorns, usually to protect themselves from predators, such as insects, birds, or animals. Show us the interesting or bizarre forms of these sharp appendages in your entries, which should be in their natural environment, not under studio lights. Macro shots are welcome. Insects or other small creatures may be present, but must not dominate the picture. Check Wikipedia for more information about this thorny subject. SIZE DOES MATTER: See below!