"Cristate" or "Crested" Saguaro (Cereus giganteus). For unknown reasons saguaros occasionally develop a disorganized growth pattern in which the growing point spreads into a line of dividing cells producing a fan-shaped tip. Some biologists speculate that the "Cristate" is a genetic mutation, but others say its a result of a lightning strike or freeze damage. It does not appear to effect the health of the plant significantly. Cristate saguaros are very rare, occurring in as few as 1 out of every 200,000 saguaros. This one was photographed in Saguaro National Park in Tucson, Arizona.