Lophophora williamsii (2018)

PhotoBy Pat Mahon (August 2018)

A cactus that has been recorded by the ancients and used since 5,700 years ago is now considered one of the most controversial species of plant in cultivation. In today’s world, all participants of the United Nations, the entire United States and its territories, along with several other countries around the world, consider the entire genus of Lophophora illegal.

This plant of the month, Lophophora williamsii, gets a bad reputation from overly concerned mothers and others involved in the U.S. War on Drugs. Hopefully, some of the negative notions can be quelled in those who cannot differentiate a lophophora from an astrophytum.

The name lophophora is derived from the Ancient Greek word lophos, meaning “the crest of a hill” or “helmet,” and phoreao, “to carry.” The etymology hints at the tufts of hair atop the plant’s tubercles. The species name williamsii was given by Charles Lemaire in 1845 to honor Sir C. H. Williams, the British ambassador to the state of Bahia, Mexico.

Lophophora williamsii was originally published as Echinocactus williamsii in a catalog without an official species description or illustration. Prince Salm-Dyck, also a botanist, submitted an official description of the new species to validate Lemaire’s binomial. However, he also did not provide an illustration.

Through many years of taxonomic confusion on how to classify this species, John M. Coulter finally hit the nail on the head in 1894. His proposition of the genus Lophophora has since evaded confusion with placing this species. In nearly 50 years, it was proposed in at least five genera, including Ariocarpus, Mammillaria and Anhalonium, before it finally landed as Lophophora williamsii.

To first hit upon the obvious, the ethnobotanical importance of this species is unmatched in the cactus world. L. williamsii is quite renowned to some for its content of mescaline as the natural drug peyote. To others, it is merely a magnificent spineless cactus that has endearing character and hides among other cacti on the greenhouse bench. Fear of the bogeyman stealing this cactus is not why we hide it, but our ironic government, which both protects Lophophora and prohibits it, makes the plant’s situation confusing.

Undoubtedly, ancient records (some over 2,000 years old) on this species are due in part to the psychotropic nature of the plant, not its pretty flowers. In 2005, a published article reported archaeological specimens of L. williamsii in Texas caves along the Rio Grande. The researchers found the plants had a 2 percent mescaline content, and radiocarbon dated them back to 3780 B.C. – making L. williamsii the oldest drug plant ever recorded.

The main psychoactive alkaloid found in lophophoras is mescaline, and the average “effective” dosage for people is 200 to 400 milligrams. To demonstrate how ridiculous it is to prohibit hobbyist cultivation of this species, a large, mature 3-inch “button” yields only 25 milligrams of mescaline.

For an effective dose, one would have to cultivate, at minimum, eight very large plants, which could take anywhere from 10 to 20 years to grow. That does not take into consideration the lessened yield of the alkaloid as a result of cultivation conditions and substrate, and if the cultivar was truly L. williamsii or one of the related species that have little to no mescaline content.

Lophophoras can contain several other ethnobotanically significant alkaloids that include pellotine and anhaladine. It is interesting to note that the species of Lophophora that produce little to no mescaline (L. fricii, L. koehresii and L. diffusa) instead carry high amounts of these latter sedative alkaloids, which are not considered controlled substances.

All of these isoquinoline alkaloids found in L. williamsii are known as secondary metabolites. To simplify this section of plant physiology, the plant makes small organic molecules for an ecological function, but they are not involved in primary growth, reproduction or development. They are, however, essential to long-term plant function.

Secondary metabolite examples could include bitter agents to deter grazing from pests (tannins), protect a plant from heat (terpenoids) or help the plant absorb or reflect sunlight (phenols). L. williamsii is interesting in that the secondary metabolites are not only psychoactive, but demonstrate an outside use. Common secondary metabolite alkaloids include caffeine and many other drugs and medicines.

The principal function of mescaline and other alkaloids of L. williamsii is not fully known, but it is likely as a deterrent to grazing by higher animals – as seen with many examples in the wild with a singular bite mark. Analysis has shown that the alkaloids contained within the cactus are also antibacterial, even shown to have killed penicillin-resistant bacteria. The cactus may have developed antimicrobial properties to defend itself from diseases and pathogens.

Piggybacking off the functions of these alkaloids, it is interesting to note that conventional approaches in taxonomy do not always apply to taxa. A proposed method in defining species and arranging the genus Lophophora is by using chemotaxonomy: classifying taxa by chemical structure similarities and deviations. This approach is proposed for several medicinal plant groups and even legumes.

The latest from Jaroslav Šnicer, Jaroslav Bohata and Vojtěch Myšák divides the genus Lophophora into two sections: Diffusae and Lophophora. Lophophora (including L. williamsii) has a mescaline content of 15 to 30 percent of the total alkaloids, while Diffusae has a maximum of 1.3 percent mescaline. This is an important approach in removing the illegal status of some lophophoras for cultivation.

With a wide distribution throughout the Chihuahuan Desert, Lophophora williamsii has deviated phylogenetically into several subspecies. Two forms of L. williamsii prevail here: northern and southern forms.

The northern form, found near Saltillo, Coahuila, Mexico, is resistant to pests and drought, and displays pink to white flowers of 1- to 2.2-centimeter diameter with pink midstripes. The autogamous northern form is able to pollinate itself with no interaction. It avoids inbreeding depression because it has through time become stable as a homozygous species.

The southern form, centered near Huizache, San Luis Potosi, Mexico, develops independent roots for each growth, instead of branching along a tuberous root system. The plants are also unusually heterogamous, producing two different flower types (male and female, or bisexual and female). Flowers differ from those of the northern form by longer styles and small stigma.

L. williamsii is found in several locations in Texas along the Mexican border. It is found at lower elevations of 100 meters, commonly distributed along limestone hills, and even at 1,900-meter elevations in the Chihuahuan Desert.

L. williamsii can be found in the Mexican states of Chihuahua, Coahuila, Nuevo Leon, Tamaulipas, San Luis Potosi and Zacatecas. The plants are most commonly found growing in association with shrubs, sheltered from the excruciating sun. L. williamsii can be found in partial sun or full sun. Undisturbed, they take on a lifestyle similar to that of Ariocarpus species, in which much of the plant is below the surface.

Another noted relationship is with non-vascular plants such as liverworts and mosses, crusts of which may ensure some moisture retention for the cactus. Field notes have reported that ants feed upon the fruits of lophophoras, perhaps a strategy in population distribution.

Supposing one were to hypothetically cultivate L. williamsii, there are a few important notes to understand. This is a very slow-growing cactus. Overwatering is possibly the most common reason for death in cultivation. Keep the plants in a coarse substrate that can dry out quickly. They favor water, but do not care for moisture retention. Keep them dry during the winter.

Amendments to the substrate such as gypsum and calcium may aid in health and flowering. Partial shade (three to six hours of direct light) is recommended, increasing as desired. Full sun (six hours or more of direct light) is not recommended.

Spider mites and mealy bugs are L. williamsii’s main pests. These pests are easily addressed, but often hide in crevices and other plants, so it is important to treat all plants in the growing area thoroughly. Plants will bloom freely throughout the year. If a plant is not blooming, it is possible it is not mature.

Surely, enough has been covered to convince everybody to go out there and purchase a beautiful Lophophora williamsii. The U.S. government has taken a firm stance on the illegal status of the genus, however, so I must urge resistance to seeking one out. In time, cactus hobbyists and researchers may be able to argue exceptions for cultivating Lophophora.

Plant Secondary Metabolism – David S. Seigler
OAKTrust Digital Repository–
Prehistoric Peyote Use: Alkaloid Analysis and Radiocarbon Dating of Archaeological Specimens of Lophophora From Texas – – CactiForum –
A Brief History of Peyote –
Peyote in the Wilds of Texas –
Key to the Genus Lophophora