Sotol (Dasylirion wheeleri) has become a staple of suburban landscapes in southwest desert communities because of its beautiful form, drought tolerance and easy maintenance. Archaeological records show that the plant has been popular with people for more than 10,000 years. To Ancient Puebloans, though, the plants were not merely ornamental. They collected and used the leaves for fiber to make mats and baskets. Young tender stalks and roots were roasted for food. Dried sotol stalks were used as fire ploughs, a method of fire making in which a dry stalk is rubbed in a wooden trough until the friction makes a hot cinder. Sweet pulp from the sotol "heart" was used to make a fermented drink much like mescal or tequila is made from agave. This drink is still popular in some parts of Mexico. Perhaps the most stunning feature of sotol is the huge flowering stalk that emerges each May from the center of a mature plant. After a couple weeks of daily measurable growth, the sotol in our neighbor's yard finally bloomed last year. The sixteen-foot tall stalk rose from the giant rosette of sawtooth-edged leaves, luring swarms of honeybees and tiny colletid bees that came to gather pollen. I've been amazed by the rapid growth of flowering stalks for over a decade, but did not realize until recently that sotols are dioecious, meaning that there are botanical equivalents of male and female plants.
Male plants bear long curly bunches of pollen-producing flowers, which sort of look like Cheetos, but without the orange dye. The sheer magnitude of the stalk and all of that pollen is truly astonishing. Likewise, females bear thousands of seed-producing flowers. Although the bees harvest prodigious amounts of pollen, they do not visit the female flowers because there is no nectar to attract them. The females must depend on wind to deliver pollen for fertilization. From a distance, you can tell the two types of stalks from one another simply by noticing the presence or absence of insect activity: male stalks are swarming with bees; female stalks may have a bird perched on top, but no bees.
Despite the fact that there are thousands of sotols growing in the Phoenix suburbs, you are unlikely to find one in nearby desert preserves. The natural habitat for sotol is much higher than our fair city, in scrublands and grasslands over 4,000 feet in elevation. They are most common in the Chihuahuan Desert, which extends from southeastern Arizona through New Mexico to Texas and Northern Mexico. If you grow sotol in your yard, you can save yourself or your landscaper from hassling with the spiny leaves by letting it grow naturally rather than "pineapple-izing" the base. Although this practice may have been a way for ancient people to harvest leaves for fiber, there is no need to remove them otherwise. Better to sit back and enjoy a shot of sotol, or just admire these hearty and majestic plants in you desert landscape.
Since May 2005, I have written a natural history column for a neighborhood newsletter published by Jennifer Moore called "Our Big Backyard: Natural History of the Deem Hills," and since 2010, "A Suburban Naturalist."All of these columns are reproduced here. Deem Hills is a City of Phoenix Desert Preserve located just north of Happy Valley Road in north central Phoenix, and just west of I-17. The Preserve and adjacent hills comprise over 900 acres of open space with several miles of hiking trails. For more perspectives from the Deem Hills and suburban Phoenix, also check out my companion blog, Kat Tracks.
As a naturalist with a special interest in botany and plant ecology, some of my greatest passions are to explore, photograph and write about native plants. If I can spark an awareness or interest in natural history in others along the way, that is my greatest reward.