To complete this achievement, you'll need to collect all land and air peyote plants located across the map.
To find the locations of said plants, I recommend the following video from GTA Series Videos:
The whole processes can take anything between one and three hours.
Note: if a plant is missing, dying once should resolve the problem, but don't explode any dinghys near the locations, they will keep the area loaded and consequently the plant will not reappear. (this, which I believe is a glitch, happened to me three times in the X/S version).
Credits: MC Mokkasyn's comment.