The True Standard: Characteristics of Peyote
The true peyote cactus, Lophophora williamsii, is the standard against which look-alikes are compared. This small, spineless cactus is globose and flattened, growing low to the ground and reaching four to twelve centimeters in diameter. Its body color is grayish-green or bluish-green, helping it camouflage in the Chihuahuan Desert.
The cactus surface is organized into straight or spiraling ribs, commonly numbering five, eight, or thirteen. Instead of spines, the plant features dense, woolly tufts of whitish hairs (trichomes) emerging from areoles along these ribs. The slow-growing species contains the psychoactive alkaloid mescaline, responsible for its cultural significance, often reaching concentrations of up to six percent when dried.
Identifying the Primary Look-Alikes
The term “false peyote” describes cacti that superficially resemble Lophophora williamsii, typically being small, spineless, and round. This visual similarity causes frequent misidentification among collectors. The most commonly confused species belong to different genera, including Ariocarpus, Astrophytum, and Epithelantha.
Ariocarpus fissuratus, the Living Rock Cactus, is a look-alike, sharing peyote’s low-growing, spineless, and camouflaged characteristics. Its body is composed of large, fleshy tubercles close to the soil surface, giving it a rock-like appearance. Astrophytum asterias, the Star Cactus, is also a small, flat, spineless cactus with a low, dome-shaped stem.
Epithelantha micromeris, or Button Cactus, is considered “false peyote” due to its small, globular shape. While not truly spineless, its dense covering of tiny, white-grey spines is tightly packed, giving the plant a uniform, woolly appearance that masks the green body beneath. This confusion is common in their native ranges, where they often grow near L. williamsii.
Key Differences and Toxicity
Differentiating true peyote from its look-alikes requires observing specific structural details. Lophophora williamsii has a smooth, bluish-green epidermis and distinct ribs. In contrast, Astrophytum asterias has a darker green stem speckled with numerous tiny white tufts of hair, a feature absent in peyote. The Star Cactus typically maintains eight low, rounded ribs, and its flowers are large and yellow with an orange center, contrasting with peyote’s smaller, pink or white flowers.
Ariocarpus fissuratus is distinguished by a body structure defined not by ribs, but by a rosette of triangular, fissured tubercles coarsely wrinkled on the exposed faces. Root systems also differ: true peyote possesses a large, tapering taproot, whereas the Star Cactus has a fibrous root system. Observing the fruit is helpful, as Lophophora fruits contain seeds only in the upper half, while Ariocarpus fruits are completely filled.
The confusion carries risk because chemical composition varies significantly, making proper identification a matter of safety. While L. williamsii contains mescaline, Ariocarpus fissuratus contains other alkaloids, such as hordenine and N-methyltyramine. Ingesting hordenine can cause severe physiological reactions, including elevated blood pressure and increased heart rate. Indigenous groups have warned that consuming this toxic substitute is more dangerous than using true peyote.