One hundred and fifty years ago America was bigger than anyone had ever expected. The plains were bigger, the prairies were bigger, and as they neared the Civil War, even the politics were bigger. Everywhere Americans looked, they seemed to find the biggest and often the best. They found the biggest gold strike in California, the biggest mountain range in the Rockies, the biggest trees, the biggest canyon, and the biggest cactus. Yes, they found the biggest cacti in the world.
When the pioneers crossed the great Sonoran Desert of the Southwest looking for a southern route to the California goldfields, they came face to face with the biggest cacti any of them had ever seen. True, many had never seen any type of cactus before, but amidst the sparse vegetation and dwarf trees of a miserly land these exotic plants stood forty to fifty feet tall, had arms like an octopus praying for rain, and lived where there
didn't seem to be enough water to keep even the grass growing. They were amazing and the people were amazed, writing back home about these “giant cactuses” and that name stuck for a while. They had met the saguaro, carnegiea giganta, and many of the very ones they stared at and scratched their heads over are still alive a century and a half later.
Like their tall redwood neighbors to the northwest and their ancient turtle neighbors on islands to the southwest, saguaros are very long lived. With claims of exceptional individuals being almost 250 years old, scientists say their average life span is just over 150 years. At two years old the fledgling plant is often less than ¼ inch tall. By time they reach one foot tall they've been around fifteen years. As they reach twenty feet tall they are between 60 and 75 years old. It is in these years that they sprout their first arms. They will keep sprouting new arms every two to three years and grow to heights taller than five story buildings. Once the symbolic sentinels of a strange frontier saguaros have endured, keeping their majesty while making a place for themselves in the modern neighborhoods and cities that have grown up around them.
One in 275 Thousand
Although there are tens of thousands of them on the hills of the Southwest, the mature saguaro is actually very rare, but not from a lack of trying. A mature plant will produce up to a hundred fruit per year on the crowns of its many arms-some have more than fifty. Each of the fruit produces in the neighborhood of 2000 seeds. So, in the century of a saguaro's mature years, a lone cactus can produce in excess of 20 million seeds. Of those millions of seeds fewer than ten plants will reach adulthood. Experts estimate that only one in 275,000 seeds reach maturity.
However, the saguaros keep trying and that's a good thing. Saguaros and their cactus cousins make up some of the most intense localized ecologies in the arid southwest deserts. Cactus seeds provide one of the main staples in the diets of desert animals such as wood rats, voles, kangaroo rats, jack rabbits, and other rodents, while the fruit and blossoms also feed birds like the white-winged dove, Gila woodpeckers, and curve-billed thrashers; long-nosed bats, insects including bees, and lizards such as chuckwallas, southwest geckos, and skinks. Each blossom which lasts just one day produces 1/6th of an ounce of nectar or 125 bee trips, for those who count such things. However, some modern research indicates that most, if not all, of the pollination of giant saguaros is done by the lesser long-nosed bats-an endangered species-since the blossoms open nocturnally and the bats get there first. It seems that in the strangeness of the desert, the early bird is a bat.
Humans also get nourishment from the saguaro. Native American tribes such as the Pima use the fruit for preserves and as a side dish. The Papago add winemaking to the uses of the green giants. Though not as popular as prickly pear, in its season-the fruit ripens in June and July, with the blossoms first opening on balmy April nights-the astute shopper can find saguaro candy in Boothill boutiques and gift shops in south and south-central Arizona.
In addition to supplying food, saguaros provide homes. Three applications of their unique structure make this possible. Saguaros are made of long, vertical ribs surrounded by a spongy pulp and an elastic skin. These ribs form ridges along which a row of thorns grow to protect it from larger predators. The thorns, called spines, are gray with a pinkish tint and grow in clusters of 15-30 per areole. Smaller spines surround longer ones that can reach three inches in length.
