A Rare Beauty, Crested Saguaro
A capstone Project Created by Don Featherstone
Cristate Saguaros, also known as fasciation, is a relatively rare condition in which the growing tip, or apical meristem, of a vascular plant exhibits abnormal growth. The apical meristem is normally concentrated around a single point which allows for approximately cylindrical growth. Instead, the tissue becomes elongated perpendicular to the intended direction of growth. This results in a flattened, ribbon like crest or elaborately contorted tissue.
Cristate are known to occur in over 100 species of plants including many cacti, aloe,acer, euphorbia, digitalis and even cannabis. It is not known what causes cristate but there are many hypotheses: A. genetic mutation B. micro-organisms C. hormonal activity D. damage due to freezing or lightning
A cristate saguaro will still produce viable flowers, fruit and possibly arms emanating from the crest. The incidence of this condition is uncertain but is believed to occur in 1:200,000 to 1:250,000.
In 2005, two members of the Tucson Cactus and Succulent Society (TCSS), Bob Cardell and Pat Hamness, created the Crested Saguaro Society (crestedsaguarosociety.org) whose mission is to find and document all crested saguaros in the Sonoran Desert. At its inception, there were believed to be approximately 200 crested saguaros in existence. To date they have documented over 2000.
Pima county 772 Pinal county 57 Maricopa county 405 Cochise county 158 Yavapai county 112 Graham county 49 La Paz county 10. Mohave county 7. Santa Cruz county 3. Yuma 2
Sources
Richard D Moore , Too Tough to Die
Amusingplanet.com Crestedsaguarosociety.org
The Botanical Review, Fasciation, vol 14, no 6
Pima Master Naturalists 
Thanks for the great article, Don. For those interested, there’s also a Facebook page, The Crested Saguaro, with 4.5K members who share their discoveries.
LikeLike