Template:POTD/2010-06-21
The prickles of a rose plant. Prickles, which are needle-like extensions of the cortex and epidermis, are often confused with thorns, which are modified branches or stems, and spines, which are modified leaves. All three are hard structures with sharp, pointy ends, which are generally used by plants to protect themselves from herbivores. Thorns likely first evolved as a defense mechanism in plants growing in sandy environments which provided inadequate resources for fast regeneration.Photo: Noodle snacks