Crested Saguaro Cactus – Desert Botanical Garden, Papago Park, Phoenix, Arizona

Even when saguaro cacti grow in their normal form, they rarely grow symmetrically. Saguaros sometimes grow in odd or misshapen forms. The growing tip of the cactus occasionally produces a fan-like form which is referred to as crested or cristate. These crested saguaro cacti, Carnegia gigantea forma cristata, are rare. Biologists disagree as to why some saguaros grow in this unusual form. Some speculate that it is a genetic mutation. Others say it is the result of a lightning strike or freeze damage. At this point we simply do not know what causes this rare, crested form.