The Desert Edge: Flora of the Guaymas–Yaqui Region of Sonora, Mexico

Date Published or Written


Richard Felger, Susan Carnahan, José Sánchez-Escalante


The Desert Edge: Flora of the Guaymas–Yaqui Region of Sonora, MexicoThis magnificent flora of the Sonoran Desert’s southern edge represents decades of meticulous work and the genius of Richard Felger (1934–2020) and his colleagues at their best. It is many things at once. A project of passion that was sparked by a trip in 1953 by an impressionable young scientist whose world was opened by canyons lined with palms, fig trees, agaves, and plants awaiting his description. The most thorough treatment of the plants of the southern half of the Sonoran Desert ever assembled, which fills a long-standing gap in the knowledge of Mexican Biodiversity. A flora brought to life by hundreds of vivid and beautiful images of the majority of the 837 plant taxa found here, most by Sue Carnahan, who brought this life-spanning project to realization with Richard and Jesús. And a flora made approachable through accurate diagnostic keys (as Richard says, “the poetry of botany”), tailored to this specific region over years in the canyons and along the coasts and countless hours at the herbarium refining measurements and decoding a floristic jumble into an orchestrated whole.

There are few areas that are as undisturbed and wild in the present age as the core area covered in this work, the Sierra El Aguaje, or as culturally important in the Sonoran Desert as the traditional Yoeme (Yaqui) land, Yoem Bwiara, the southeastern area of the flora. These regions represent distinct geographic and historical underpinnings, though they are linked by an under appreciation of their diversity and lack of formal protection. The information provided here presents an unparalleled documentation of the plant life of the 532,000 hectares of the desert edge that will support future efforts for increased recognition and culturally inclusive conservation. Importantly, this work is freely accessible in its digital version for use in the field or at home by a wide audience, especially in Mexico.

Yet collectively, this work is more than each of these elements. It is a work of scientific rigor and an ode to one of the special parts of our world by one of the greatest botanists ever to focus their keen eyes on the Sonoran Desert. Richard, Sue, and Jesús have created a testament to the remarkable plant life that bridges the tropics and the desert, and the sea and the sierra. As one of Richard’s last works, it is another gift to those who love this region and crave an opportunity to better understand its richness and have a guide to interpret what we see in our explorations. I have no doubt it will stand the test of time, and I hope it encourages us to cherish our teachers and preserve the beauty of our world.

Benjamin T. Wilder January 2023

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