The Baboquivari Mountains, long considered to be a sacred space by the Tohono O'odham people who are native to the area, are the westernmost of the so-called Sky Islands. The mountains form the border between the floristic regions of Chihuahua and Sonora. This encyclopedic work describes the flora of this unique area in detail. It includes descriptions, identifications, ecology, and extensive etymologies of plant names in European and indigenous languages...