Oh My Agave!

by Joe Hughes

The mention of our neighbor to the south typically conjures up images of sunny beaches, arid deserts and plateaus, a rich cultural history, delicious cuisine, and of course tequila. So, on a recent trip to Mexico City it came as no surprise to see the landscape dotted with agave, cacti, and various shrubs, growing ever more frequent as we slowly made our way out of the bustling city and toward Teotihuacan. It was here, at a well-established tourist outpost just outside of the ruins, that we were introduced to the many uses of the agave that can be found all over the area.

Most notably to us, agave is the main component in the production of tequila or mezcal. At Teotihuacan, visitors are able to enjoy a tasting tour through the various spirits that can be made from agave. We began by tasting pulque, a “non-distilled traditional alcoholic beverage produced by the fermentation of the [agave] sap known as aguamiel” (Escalante et al., 2008). This sweet, viscous, milky drink had a mild sugariness that was very pleasant, with the texture of a smoothie I had made in my blender at home. We then moved on to sampling some mezcal, a liquor that is much more similar to the tequila that many are familiar with, with one important distinction. Katie Robbins at Delish (Robbins, 2021) states that “while mezcal can be made from a blend of one of 250 types of [agave] to be classified as tequila, a bottle must be at least 51 percent blue agave (Agave tequilana).” Similarly to champagne, tequila must satisfy these certain conditions to be considered truly tequila, otherwise it is a mezcal. What better venue for this lesson than at the ruins of an ancient metropolis at 10:00 in the morning?

After a healthy amount of samples, our guides continued to explain that these herbs can provide many other products besides just spirits. The Maya and Aztecs, who lived across what is now Mexico, have been utilizing these plants for the past several thousand years to construct crude fabrics, papers, and tools that could be used for a multitude of purposes (Siegler, 2005).

Though there are many species of agave in cultivation, there are a few species (notably Agave sisalana [sisal] and A. fourcroydes [henequen]) that are cultivated specifically for their ability to produce long, durable fibers that can be made into a variety of useful textiles. These fibers are acquired by scraping away the upper layers of each large, rigid leaf and “hand stripping” these fibers out of the plant, in a process called decortication (Future Fibers, 2022). The fibers must then be dried and brushed before they can be processed into a textile for use by humans. Fibers achieved through this process can be used in a variety of different ways. Most simply, these fibers can be woven into a durable thread and used as is. In turn, this thread can be further manipulated into string or twine, as well as textiles for clothing and carpets, and is especially useful nowadays as a buffing cloth for steel (Future Fibers, 2022). At a shop just outside Teotihuacan, these fibers have been used to make a wide variety of souvenirs and trinkets, in a bit of a departure from its historic utilitarian purpose.

These plants can also provide other sorts of products from different methods of harvest. The sharp prickles that grow at the end of agave leaves can be used as a needle, in conjunction with the sisal thread, to sew together pieces of sisal textile. The uppermost layers of the leaves can be used as a sort of paper, once peeled off into a thin, flexible sheet. A paper can also be made by pressing the pulp of the agave plant, in a manner more similar to that of paper production with woody pulp.

These agave fibers played an important economic role across southern Mexico until the early 20th century, when the introduction of synthetic plastic fibers at a much lower cost caused demand to shift away from the naturally occurring sisal. The industry faced other challenges as the world around it globalized, with sisal production being brought to Brazil and East Africa in a bid to increase production and profits. These areas, though similar in climate, have since outpaced Mexico in sisal production (Vuorinne, Heiskanen, & Pellikka, 2021). This was achieved by straying slightly from the traditional methods of cultivation, harvesting, and processing used by the Maya and Aztec peoples, and utilizing technology that was unavailable a few centuries ago.

Efforts are being made to restore the historic levels of sisal production in Mexico, as well as globally, in a bid to combat the increased dependence on synthetically produced fibers. Through groups like the Food and Agriculture Organization of the United Nations, emphasis is being placed on building sustainable production mechanisms that can satisfy global demand with a supply of natural sisal fiber. 

Visiting this ancient city was a wonderful experience that I cannot recommend highly enough. If seeing an archaeological wonder up close, coupled with a lesson on agave-based alcohol aren’t enough, consider the knowledge you can gain on the importance of utilizing the natural resources we have been provided by this planet, as opposed to concocting synthetic stand-ins. This experience is evidence enough we still have more to learn from the many, many generations that came before us.

Photo Credits: 1) Agave sisalana cultivated at Cooktown Botanic Gardens (Lokal_Profil, via Wikimedia); 2) Bottle of pulque (Alejandro Linares Garcia, via Wikimedia); 3) A. sisalana U.S. National Arboretum Herbarium Specimen with extracted fibers included; 4) Blanket made from Agave fibers (J. Hughes); 5) Pyramid of the Moon, Teotihuacan (J. Hughes)

References

Escalante, A., M. Giles-Gomez, G. Hernandez, M.S. Cordova-Aguilar, A. Lopez-Munguia, et al. 31 May 2008. Analysis of bacterial community during the fermentation of pulque, a traditional Mexican alcoholic beverage, using a polyphasic approach. International Journal of Food Microbiology 124:126-134. Accessed October 10, 2022. Available from: https://www.sciencedirect.com/science/article/pii/S0168160508001244 

Future Fibers: Sisal (Internet) Food and Agriculture Organization of the United Nations. Accessed October 4, 2022. Available from: https://www.fao.org/economic/futurefibres/fibres/sisal/en/

Robbins, Katie. 2021. There’s only one kind of mezcal you’ll find worms in. Delish. Accessed  October 10, 2022. Available from: https://www.delish.com/cooking/news/a38585/waiter-theres-no-worm-in-my-tequila/

Siegler, David S. April 2005. Fibers from plants. University of Illinois, Urbana. Department of Plant Biology. Accessed October 4, 2022. Available from: https://web.archive.org/web/20130804031742/http://www.life.illinois.edu/ib/363/FIBERS.html

Vuorinne, I., J. Heiskanen, P.K.E. Pellikka. 12 January 2021. Assessing leaf biomass of Agave sisalana using Sentinel-2 vegetation indices. Remote Sens 13(2):233. Accessed October 10, 2022. Available from: https://www.mdpi.com/2072-4292/13/2/233 

 

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Joe Hughes is a graduate of The George Washington University (2021) and in his second year as an ORISE intern at the U.S. National Arboretum Herbarium. In his free time he enjoys traveling and exploring parks around Washington, D.C.

“Hazards” of the Job: Dealing with Plant Defenses in the National Herb Garden

By Chrissy Moore

I’ve never been much of a daredevil. Overactive amygdala, perhaps, or maybe I’m just a ninny. (Usually, the latter.) And yet, I’ve always admired those individuals who brave dangerous situations for the good of others: firefighters running toward the flames; avalanche search and rescue teams; Alaska’s Coast Guard members that jump into frigid waters during gale force winds…you get the idea.

Today, I had an epiphany while watering our myriad plants in the greenhouses. Most people think that herb gardening is a quaint, bucolic endeavor, which, admittedly, has a ring of truth to it. But, those people have never worked in the National Herb Garden (NHG), where we, too, face dangerous situations on a regular basis, just of the botanical sort.

For example, every year, twice a year, the NHG staff and coworkers haul many large containerized plants into and out of the greenhouses, where they spend the winter months. Many of these plants are loathsome creatures, not just because of their size (try hauling and lifting hundreds of pounds of “dead weight” for hours at a time…hope you didn’t water them the day before!), but because of the physical hazards they present. It is not unusual for plants to employ natural defenses to protect themselves from malevolent insects or browsing animals, etc. That’s understandable. Yet, when we—the benevolent humans assigned to be their nurturing handlers—are subjected to that very same botanical weaponry, it seems just a wee bit like unnecessary punishment. But, no one ever said life was fair.

Let’s look at our beloved Citrus plants. These shrubs have beautiful flowers with a glorious scent and delectable fruit. What’s not to love? Most people only get the occasional painful squirt of acidic juice in their eye when peeling the fruit. Yeah, not us. We are repeatedly stabbed by the plants’ two- to three-inch long thorns all over our bodies and, heaven forbid, in or around our eyes. To paint the picture for you better, our method for moving all of the plants in and out of the greenhouses is by a hand truck. So, the whole upper half of our bodies is engulfed by the plant’s canopy. For the Citrus, one puncture wound is bad enough; multiple punctures is just plain mean.

A few years ago, I was visiting friends in Málaga, Spain. It was interesting to see large, in-ground specimens of plants that we can only grow in containers in the NHG. One of them, Phoenix dactylifera (date palm), is one of our more hated plants to move in the garden. (If only we could grow ours in the ground!) Like many palms, the fronds have sharp points at the end of every leaflet.

And like the Citrus plants, our date palm gets hauled around on the hand truck, with all the fronds right at face level. Death by a thousand stabs. To get the plants into their final positions, we need to navigate the narrow greenhouse walkways, which takes a lot of coordinated effort between the one hauling the plant and the person doing the guiding; more often than not, the person doing the hauling can’t see past the plant and must navigate by auditory cues rather than visual ones. As you might imagine, this only adds to the danger!

Moving the date palm

My personal “favorites” each have minor variations on the armament theme just to keep you from getting complacent: pineapple (Ananas sp.) has upward-facing prickles along its leaves; Agave sp. has outward-facing prickles; and cascalote (Tara cacalaco) has downward-facing prickles. These are what I consider the plant versions of the Chinese finger torture: the more you dive in or pull back, the more caught you become. And, by default, the more stabbing you experience. Agave plants, in particular, are awkward to maneuver on a good day, but ours range in size from three to four feet across and two to three feet tall. Given their sprawling nature, there’s not even the remote chance of using a hand truck to move them.

Ananas sp. (pineapple)

Agave sp. (agave)

You must fully embrace the pain by lifting them from the ground just under their “waists,” like a child that’s really just too big to be picked up anymore. “Bend with your knees!” has little bearing on this activity. If we’re being honest, we’re just trying to fling that thing to its final resting place as fast as we can and from whatever “reasonable” posture we can attain, wrecked clothing and hairdo be damned. How do those folks at the Desert Botanical Garden in Arizona do this day in and day out? No thanks…trying to quit. My assistant, Erin, is the smart one; before handling an agave, she nips the spines off with her pruners. Duh! Why didn’t I think of that?

Cascalote, while sporting dainty, pinnately compound leaves, is actually a botanical death trap. Like the agave, pineapple, and Citrus combined, its prickles are not only curved for maximum entrapment, but they also cover the entirety of the plant, nearly from head to toe. The only thing in its favor (at least for our specimen) is that it has a generally upright growth habit rather than being wild and ungainly like the pineapple and agave. Thank goodness for small blessings, short-lived though they may be. Getting caught in the cascalote is like getting sucked into quicksand—the more you move, the worse your situation becomes. I did say Chinese finger torture, didn’t I? (Side note from Erin on moving our cascalote: “Man, after moving that Tara this go around, I got home that night and had a thorn still stuck in my leg. It had worked its way through jeans and a thermal layer to hitchhike and irritate me all day. I still have a little scar!” See! We’re really telling the truth.)

The last, but certainly not least, plant on my list is sugarcane (Saccharum officinarum)—and, frankly, most species in the grass family (Poaceae). If you’ve never worked with a grass of sugarcane’s magnitude, then you haven’t met the devil incarnate…yet. It hides its weaponry really well, so you’re more likely to forget rather than be vigilant. Sugarcane is replete, not only with irritating hairs (called trichomes) at the joints along the stem that wiggle under your clothing and irritate your skin to no end, but the leaves themselves sport razor sharp edges in a pattern similar to a sawmill blade. The leaf edges slice human skin with the accuracy of a piece of notebook paper. Yep, paper cuts are my fa-a-a-vorite! “What? You don’t enjoy paper cuts? Hmmh, go figure!” Handling sugarcane takes a bit of forethought and a deft hand. The trick is to pick up the plant so that the leaves are directed away from your own body and hopefully not toward your coworkers who are naïvely standing nearby. Invariably, though, someone will get a little too spirited in their moving, and suddenly, we’re all running for cover like kids at a piñata party.

While not all of our plants create perilous situations (parsley and oregano are pretty benign…or are they?), we certainly hear a lot of grousing and grumbling from our coworkers and volunteers when moving day arrives…sometimes under muffled breath and sometimes hollering from the top of their lungs. That’s when you shrug your shoulders and say, “Just another day in the life of the National Herb Garden! Someone get the First Aid Kit.”

Author’s Note: I regret to inform our readers that the Phoenix dactylifera has moved on to greener pastures (pun intended). We finally decided that it was getting too big for safe handling and preferred to start anew with a smaller specimen. Our bodies are grateful for that decision.

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Chrissy Moore is the curator of the National Herb Garden at the U.S. National Arboretum in Washington, D.C. She is a member of the Potomac Unit of The Herb Society of America and is an International Society of Arboriculture certified arborist.