Tia Marta here to share a “culinary-plus” discovery. On a spring hike into King Canyon up from the Desert Museum, Tucson Mountain Park, I was thrilled to see a delicate flower show right along the arroyo margins. It was a veritable shower of creamy yellow pea flowers on a normally non-descript twiggy bush Coursetia glandulosa.
The cute-sy “baby bonnet” flowers drew me in for a closer look and another surprise awaited me on its hidden stems. What in the world was that gross-looking orange/amber waxy stuff like a growth on the twigs? I had to find out.
My inquiries met with lots of “I donno’s” until I asked the go-to person at the Desert Museum, educator and plantsman Jesus Garcia, who exclaimed, “You found Goma de Sonora!”
An interesting story emerged. He said how traditional people of Sonora used to harvest it as actual food–a healthful nutrient! This gum-substance is exuded by a piercing-sucking insect (Tachardiella fulgens in the Order Hemiptera) as a protective shield from predators and the elements as it draws nutrients from its host plant. I learned from ethnobotanists Drs.Robert Bye and Adelmire Linares of Universidad Autonoma de Mexico that Native people including the Raramuri (Tarahumara) of the Sierra Madre used it not only as food but also as a remedy for poisoning. It is even reported as a dye material. Traditionally, the Tohono O’odham also used this translucent, orange-brown gum as an adhesive mixed with adobe to tightly seal their jars of bahidaj sitol (saguaro fruit syrup). Talk about multi-use!
I chipped off a tiny pea-size piece and tried tasting it—an unusual flavor and a crunch, with a hint of the sugary sap that the insect sucks through its piercing mouthparts. Amazing to learn that it is now being used in innovative gastronomy as flavoring for salsas and aguachiles. (See Wikipedia for a good aguachile recipe.) [By the way, this goma de Sonora is not to be confused with another Goma or Gomaae, a Japanese roasted sesame sauce.]
I’ve only found it twice in all my desert walking and am wondering if goma de Sonora has become rarer in recent times. Is climate change limiting the specialized insect-instigator? If you find it, best to only taste it– or better still–just appreciate its past uses, as it is so rare. Goma de Sonora was reportedly once harvested throughout the whole range of Coursetia from the dry tropics of northwest Mexico into the Sonoran Desert of SW United States. Let’s enjoy this curiosity of Nature and its ethnobotanical history without damaging it. Bring your magnifier on your next hike to check out this crusty little wonder if you are blessed with an actual sighting.
Production of goma de Sonora is a good example of commensalism–in this case the insect not harming the plant. It is an external process. Many desert plant species produce their own gums internally, a significant component of their survival strategies for preventing water loss—as in “gum-Arabic” and “gum-acacia”. Nutrients found in desert plant gums are a super-important part of traditional Desert People’s healthy diet, so stay tuned for another blog….
Tia Marta wishing you happy explorations for Coursetia‘s treasure–goma de Sonora!