^BCactus bristles.^b Coloured scanning electron micrograph (SEM) of bristles (glochids) on a cactus of the family Cereoideae. Bristles are used by cacti as a method of protection from grazing animals. They are barbed so as to enter skin easily, but to be difficult and painful to remove. They develop from buds on the cactus’ stem.
Vide Grenier 