Willows are common all along the Rio Grande and other wetland areas in the Chihuahuan Desert. Although several species occur, all have been known in folk medicine since time immemorial. Chewing leaves or use of infusions from the bark alleviated pain and fever. In early European medicine, the Doctrine of Signatures was accepted. This was the belief that the appearance or characters of a plant signaled its medicinal use. Thus the relief of joint pain could be related to the flexible limbs of the weeping willow, or the ability to reduce fever to the fact that both willows and fevers thrived in damp areas.
By the 1820s, the chemical salicin, named after the genus of willows,
Salix, was isolated. Later, treatment with an acid produced salicylic acid--a
substance that is formed naturally in stomach acid from salicin. Although a frequent
cause of nausea and gastric upset, salicylic acid became widely used in medicine. An
additional chemical discovery resulted in acetylsalicylic acid, much gentler on the
digestive system--the willow's gift is now ours in the form of aspirin.
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
A Coyote Willow leans over the "Hueco" at the Chihuahuan Desert Gardens. Photograph by A.H. Harris.