What Are the Stickers for on a Cactus?

Security

• One purposes of spines, or stickers, on a cactus is protection from animals. Because a cactus must survive on so little water, it must find a way to protect its water supply from other living things. Cacti have spines that painfully penetrate an animal's skin, so they keep away unwanted predators and allow for water retention.

Keeping Cool

• Cacti needles also allow for a certain amount of shade for the plant. Some plants' needles are very large to allow for a greater amount of shade, while others have more numerous needles for more shade as well. As most cacti needles are white, this allows the plant to deflect some of the sunlight and help keep the plant cool.

Water Preservation

• Another purpose of some cacti spines is water retention. When there is rain, fog or even early morning dew, the cacti needles gather those drops of water for the cactus. The water gathers on the spines, which transport the moisture to the stem of the cactus.

Reproduction

• Most cacti reproduce in the normal plant way. Insects spread pollen from flowers to others and they continue to reproduce. Some cacti spines serve as a continued reproduction method of its species. The stickers attach to animals and then fall off or they drop directly to the ground, where they can take root and begin growing a new cactus.