D e s e r t E x p o s u r e
January 2012
Southwest Wildlife
The Noble Agave
The plant that gives us mescal and tequila also bestows a literally once-in-a-lifetime blooming display, when the agaves flower themselves to death. Named after the Greek term for "noble," the agave, with its distinctive rosette, or spray-like, arrangement of succulent leaves, bears a clear resemblance to its botanical relative, the yucca.
Story and Photos by Jay W. Sharp
Like the yucca (see "The Giving Tree," December 2011), the agave serves as a food and material resource for various animals. But the agave, unlike the yucca, also yields raw stock for several potent beverages that give a whole other dimension to the notion of nature's "food chain."
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The century plant approaching full bloom. |
The agaves, which include more than 200 species, evolved, like the yuccas, in the New World. Their range extended from southern Nevada and southern Utah across our Southwestern deserts down through Mexico and Central America and across into Caribbean islands. Since the 15th century, their range has expanded across the Atlantic, propelled primarily by the Europeans. For instance, I have seen the Agave americana — the classic "century plant" — growing in Algeria, a former French colony, in village gardens near the Mediterranean coast.
More than a dozen species of agave grow in the Southwest, especially in the desert grasslands of the basins and in the wooded foothills of the mountain ranges. They seem to prosper on slopes that have slightly acidic soils and a rocky overburden.
The typical, relatively massive agave leaf, with its stiletto point and wickedly barbed edges, would serve as a weapon for Conan the Barbarian. The typical Southwest yucca leaf, by comparison, with a more rapier-like shape and mere filaments along its edges, would better serve as a weapon for Zorro.
In some Southwestern species, an agave leaf rosette may span perhaps a foot and a quarter; in others, several feet. The leaves' rosette arrangement and channel shapes serve to funnel rainwater to the heart of the plant. The leaves range in color from green to grayish green to bluish green and often bear decorative bands in various shades of green and brown. They vary in shape from short and thick to relatively long and narrow, with some laser-beam straight, others elegantly recurved, and still others inelegantly twisted and bent. Sometimes leaves bear imprints from the tight clasp of neighboring leaves before their rosette fully unfurled.
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The agave leaf’s stiletto-like point. |
The agaves' leaves, according to John Moore of the Colorado State University Cooperative Extension Demonstration Garden, have special cells for water and food storage. In fact, he notes, "All the water storage and energy storage of the plant is in the leaves." Like yuccas, the agaves — in a botanical strategy designed to minimize water evaporation — open their stomata (leaf pores) during the coolness of night to gather the carbon dioxide they will need for photosynthesis during the sunlight of the following day.
Most agaves have a very abbreviated stem. Indeed, the leaf rosette for those species almost seems to spring directly from the roots. (Some yucca species — our Lord's candle, for instance — have little or no stem, but various others such as the torrey, soaptree and Joshua tree yuccas often have stems that range from 10 to 20 feet or more in height.) Some agave species produce small plantlets — clones sometimes called "pups" — from their abbreviated stems, at the base of their leaf rosettes. "In this way," according to the Arizona-Sonoran Desert Museum, "clones (multiple, genetically identical, individuals that originated from a single seed) form colonies that may persist for centuries or longer."
The agaves, like some yucca species, have shallow, fibrous, radiating root systems that race against competing plants' root systems as well as high evaporation rates to capture as much water as possible from the desert's infrequent rainstorms and snow melt.
An agave, unlike a yucca, spends years, often decades, accumulating water and carbohydrates in its heart, preparing for a seminal and life-ending event — the botanical ritual of blooming. When it matures, having stored sufficient resources, the agave begins to flower, producing its blossoms during the summer and early fall. According to the Arizona-Sonoran Desert Museum, "The carbohydrates provide the energy that fuels the rapid development of the inflorescence (the flowering structure, including supporting stems), which is usually massive compared to the plant that produces it. In all but a few species the rosette dies after flowering and fruiting, having spent all of its life energy to produce a huge quantity of seeds…. The plants literally flower themselves to death."
In their closing days, memorialized by white to yellowish white to orange or greenish blossoms, some agave species flower during the day, inviting hummingbirds as well as bees and other insects to feed on an abundant reservoir of nectar in return for the critical service of pollination. Other species flower during the night, attracting not only hawk-moths and other nocturnal insects, but also long-nosed bats, with a banquet of foul-smelling nectar, receiving payment by way of pollination. Indeed, according to the Smithsonian's National Zoological Park website, "An estimated 100,000 lesser long-nosed bats… converge on southeastern Arizona in late summer for the agave bloom, and an even larger number feed on agaves not far south, in the Mexican state of Sonora. These gray and cinnamon-brown creatures are valuable pollinators of the cacti and agaves they frequent."
Family Members
Like other desert succulents, especially the prickly pear cacti, the agaves almost seem to take a perverse delight in confounding taxonomists — the scientists who would classify and name the plants. As far back as 1871, Sir Joseph Hooker, a famed English botanist, remarked that the agave species were "difficult to name accurately." Authority Jan Kolendo, who quoted Hooker in "Issues of Agave Nomenclature," published on the Globalnet website, added, "The confusion continues to this day…. There are so many unresolved issues that agavologists will be kept busy for some time to come." The agaves confuse the "agavologist" still further because they have migrated so much in the company of both prehistoric and historic man that biological scientists sometimes have trouble tracing individual species back to their origins.
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Patch of lechuguilla or shindagger agave, located in Anthony Gap, between the Organ Mountains and the Franklin Mountains. |
A few of the more notable agaves in our region include the mescal agave (Agave neomexicana), the lechuguilla or shindagger agave (Agave lechuguilla), the desert agave (Agave deserti), and the classic century plant (Agave americana).
The mescal agave, especially common in southwestern New Mexico, grows in grasslands and on limestone shelves up to several thousand feet in elevation. A small- to medium-sized, tough and resilient agave, it produces numerous pups. Like most other agaves, the mother plant dies once it has bloomed. The mescal agave was an especially important food source for the Mescalero Apache, whose name comes from the plant.
The lechuguilla or shindagger, a formidably armed plant that stands as a symbol of the Chihuahuan Desert, grows sometimes as a labyrinthine mass of fierce botanical dirks and daggers on foothills at elevations of 4,000 to 5,000 feet. Also common in southwestern New Mexico, "this formidable plant was a dangerous obstacle in early Southwestern exploration," notes James A. MacMahon in his Audubon Society Nature Guide, Deserts. "The sharp leaves pierced horses' legs and a rider who fell might lie impaled. Today, leaves of small plants puncture tires of off-road vehicles."
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| Agave leaves in tight embrace, before they become fully unfurled. You can see the imprint of an embrace on the leaf at the lower right. |
The desert agave, also relatively small, grows primarily in the Sonoran Desert. As the name suggests, the species — which may husband its resources for decades before it flowers — has adapted superbly to the desert, even the harsh lower Colorado River Valley region. Its stem produces plantlets, slow-growing siblings (or pups) that may form a dense circle around the mother plant. "Rings 20 feet… in diameter in California's Anza-Borrego Desert State park may be more than a millennium old," according to the Arizona-Sonoran Desert Museum.
The century plant — and here I'm referring specifically to the Agave americana — qualifies as one of those of uncertain origin, although it occupies a wide range in Mexico and, more recently, in our deserts of the Southwest. Tolerant of diverse climates and soils and a prolific producer of pups, the century plant "has spread throughout the temperate and tropical areas of the world," according to the Succulent Plant Page website. One of the larger of the agaves, the century plant rosette may reach seven or eight feet in height and span 12 feet in width, with individual leaves reaching six feet in length. It produces a bloom stalk that may reach 30 to 40 feet in height. It has been called the "blue steel" agave, a reference to the color of its leaves.
In the Food Chain
Although they present their nectar, like fine wine, to their insect, bird and bat patrons, the agaves, especially compared with the yuccas, tender a sparse salad bar for a relatively small number in the wildlife community — for instance, bighorn sheep, javelinas and rodents. The plant may in fact be toxic for some animals, including, for example, rabbits. Agave weevils do manage to chew into the leaves, and according to the Maricopa County Cooperative Extension Home Horticulture website, "They lay eggs into the holes and the larvae burrow into the plant to feed. Agaves collapse into a putrid, rotting mess during late summer as a result of bacterial rot and internal infestation of agave weevil larvae."
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A century plant (Agave americana) with a new bloom stalk, which signals its final days. |
The agaves nevertheless have held high importance for thousands of years as a commodity in the economies of Native American peoples across the Southwest and deep into Mexico. Harvested just prior to flowering, when the plant's energy storage reaches its peak, an agave, roasted, becomes a "sugary, high calorie and nutritious food," according to The Marana Community in the Hohokam World, by Suzanne K. Fish, Paul R. Fish and John H. Madsen. I've eaten roasted agave. It tastes slightly sweet, maybe much like cucumber or squash. It may be high calorie and nutritious. It is certainly chewy.
Agave roasts meant brutal, back-breaking and probably communal labor for the Native Americans. The Mescalero Apache women, for instance, joined together for the roast in the spring. First, they had to free the agave heart from the rosette in the desert soil. In prehistoric times, they had to use "agave knives" — broad, flat stone tools with flaked cutting edges — to slice the heavy, spiny leaves away from the rosette, leaving a pineapple-shaped heart that might weigh as much as 50 or 60 pounds.
Next, the Mescalero women had to dig large roasting pits, which they filled with firewood topped with flat stones, according to James L. Haley in his book, Apaches: A History and Culture Portrait. Following a traditional ritual — blessing each part of the plant — they lit the firewood, allowing it to burn down to the coals. They covered the heated flat stones with damp grass. They placed the agave hearts on the damp grass and covered them with more damp grass, then topped off the pit with soil. They then built another fire on top of the filled pit, beginning several days of roasting. When the agave hearts had cooked fully, the Apache women had to dig them from the pits and carry them on their backs, in "burden baskets," to their camps. There, they preserved the roasted agave hearts by drying them in the sun.
Near prehistoric and historic Indian campgrounds across the Southwest — for instance, along the western flanks of the Guadalupe Mountains — you can still find archaeological evidence for agave roasting pits, often marked by large concentrations of fire-cracked rocks. You can even find surprising archaeological evidence for agave agriculture in some areas.
Beyond their role in the food chain, agave flower stalks are used by birds for nesting and perching, and, according to Moore, man has used the agaves for "soap, clothing, rope and other fibers, needles and thread, paper, glue, weapons, military instruments, medicines, red coloring matter, forage and ornamental and hedge plants."
Pulque, Mescal and Tequila
If the agaves have served both a food-chain and a utilitarian purpose in the economies of prehistoric and historic peoples in the deserts of the Southwest and in Mexico, they have found true botanical stardom as a source for the liquids used in fermenting the intoxicating drinks called "pulque," "mescal" and "tequila." The sugar-rich juices from the leaves of mature plants can be fermented into pulque, according to the Arizona-Sonoran Desert Museum: "Steamed heads or central stalks are mashed and allowed to ferment with added liquid. After several days, the resulting fluid is distilled in the potent liquor mescal…. Tequila, the most famous legal variety of mescal, is made from the single species Agave tequilana, grown near the town Tequila in Jalisco. Tequila is to mescal much as Chardonnay is to wine."
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| Mescal agave in bloom atop a cliff in the Organ Mountains. |
As I can testify from my partying days more than 50 years ago at the University of Texas at Austin, tequila is to a hangover much as a siren is to a headache.
"Throughout the history of the New World the agave has been closely associated with mankind in a multitude of ways," according to "The Agave: A Plant and Its Story" by Jan Kolendo. "In the pre [Spanish] conquest era [in Mexico] the agave was well established as an important feature of everyday life and religion and played an important role in the human sacrifice which especially the Aztecs practiced to such an extent [that it] horrified even Cortez and his soldiers…. These [sacrificial] events seem to have been marked by the consumption in large quantities of pulque." Victims were taken to the temples and given pulque to drink, while the priests' "enthusiasm for sacrifice" was fueled by drinking pulque. On a typical sacrificial night, all the celebrants participating would carry on drinking the pulque without restriction.
The agave moved seamlessly from the ancient cultures of the Mesoamerican city states into the new cultures of the post-conquest Southwest. That gave rise to the dicho (saying) recorded in "Tequila: A Natural and Cultural History" in The New Farm:
"Para todo mal… mescal… para todo bien… también!"
"For everything bad… mescal… for everything good… the same!"
Jay W. Sharp is a Las Cruces author who is a regular contributor to DesertUSA, an Internet magazine, and the author of Texas Unexplained. To read all his guides to wildlife of the Southwest, see www.desertexposure.com/wildlife.