Cristate or “crested” saguaros form when the cells in the growing stem begin to divide outward, rather than in the cir-cular pattern of a normal cactus. This is an unusual mutation which results in the growth of a large fan-shaped crest at the growing tip of a saguaro’s main stem or arms.

Some saguaros grow in rare formations called a cristate, or "crested" saguaro. This growth formation is believed to be found in one in roughly 10,000 saguaros, with 2743 known crested saguaros documented. The crest formation, caused by fasciation, creates a seam of abnormal growth along the top or top of the arm of the saguaro.

These freaks of nature are called crested, or cristate, saguaros, and can assume many forms, from the exalted ring crest (only 71 are known to exist) to a myriad of wild natural designs. The exact reason they grow as they do is not conclusively known. Possibilities are lightning strikes, frost damage, a hormone imbalance or a genetic flaw.

Saguaros sometimes grow in odd or misshapen forms. The growing tip occasionally produces a fan-like form which is referred to as crested or cristate. Though these crested saguaros are somewhat rare, over 75 live within the boundaries of the park. This growth pattern occurs in other plants where it is known as fasciation.

The crested Saguaro cactus is a majestic beauty. Each cactus sports a unique shape and intricate formation. The cause of this strange growth is unknown. Some believe it’s a genetic defect, while others believe it is caused by lightning. Either way, these unique crested saguaros are among one of the rarest species of plants in the world.