Peyote is native and endemic to North America with a north-south range of some 800 miles in the United States and Mexico. The Lophophora genus (of which peyote, or Lophophora williamsii, is a member) is one of the most wide-ranging of all the plants occurring in the Chihuahuan Desert. Most of that range occurs in Mexico in the valley between the Sierra Madre Occidental and the Sierra Madre Oriental: an area of some 60,000 square miles. In the US the Texas borderlands form the northern edge of peyote’s range. 

The thornbush vegetation type that dominates much of the south Texas landscape has floral affinities with that of northern Mexico, named the “Tamaulipan Brushlands.”