Kew’s Plants of the World Online accepts four Lophophora species: Lophophora williamsii, L. diffusa, L. fricii and L. alberto-vojtechii. A fifth name, L. koehresii, is recognised by the Czech authors who described the modern genus concept and sunk into L. diffusa by Kew. This page puts all of them side by side: the same characters in the same units, a sortable table, an identification key, the published alkaloid measurements, and the naming history from 1839 to 2022. At rarecactus.com we built this comparison by cross-checking Kew POWO’s accepted names against the published alkaloid and morphology literature, so the table reflects current taxonomy rather than the older varietal names still circulating online. It is the comparison companion to the Lophophora genus hub.

How many species of Lophophora are there?

There are four accepted Lophophora species and one disputed population. The genus splits into two sections: section Lophophora holds only L. williamsii, the mescaline-dominant peyote of Texas and north-central Mexico, while section Diffusae holds L. diffusa of Querétaro, L. fricii of the Viesca basin in Coahuila, and the dwarf L. alberto-vojtechii of northern San Luis Potosí and Zacatecas, all of them pellotine-dominant. The eastern San Luis Potosí plants published as L. koehresii sit in the table as a population of L. diffusa, with a note, because that is where Kew places them. Use the Sort by control below the table to reorder it.

Rib count and rib definition do most of the work. L. williamsii carries five to thirteen clearly defined ribs, usually eight, on a blue-green body of 2 to 8 cm. L. diffusa has seven to thirteen ribs so flattened they read as rows of tubercles on a soft yellow-green body that can reach 12 cm. L. fricii pushes rib count to as many as twenty-one, poorly defined, on a grey body of similar size. L. alberto-vojtechii stays under 25 mm across at maturity, which no other species in the genus does. The full Lophophora williamsii, Lophophora diffusa, Lophophora fricii and Lophophora alberto-vojtechii pages carry the habitat, cultivation and locality detail this table compresses.

How do you tell Lophophora diffusa from Lophophora williamsii?

Body colour and rib definition separate them before the plant ever flowers: L. williamsii is blue-green with clear ribs and a pale pink flower, while L. diffusa is yellow-green and soft with ribs flattened into tubercle rows and a white to cream flower. The chemistry agrees. L. williamsii is mescaline-dominant; L. diffusa is pellotine-dominant with mescaline absent or at trace level. Range settles any remaining doubt, since L. diffusa is endemic to Querétaro at 1,400 to 2,100 m and L. williamsii never reaches that state. Seed and nursery stock sold under either name is often mislabelled, which is why the key below asks about provenance last, not first.

Identify your plant

Four questions, no login, and a shareable result. The key uses the same characters as the table: flower colour, rib definition, body size, and where the plant or its seed came from. If the plant has spines, a leafy rosette or milky sap it is not a Lophophora at all, and the general cactus identifier is the better tool.

Which Lophophora species contain mescaline versus pellotine?

Only Lophophora williamsii is mescaline-dominant; L. diffusa, L. fricii, the koehresii population and L. alberto-vojtechii are pellotine-dominant, with mescaline absent or at trace level. No alkaloid analysis of L. alberto-vojtechii has been published; the only figure for its section is 1.3 percent of the total alkaloid fraction in the koehresii population, a share of the alkaloids rather than a dry-weight percentage, so it cannot be compared with the figures below. That split is the chemotaxonomic backbone of the genus and the reason the two sections were erected. Within L. williamsii the published mescaline figures range from roughly 0.1 to 6.3 percent of dry weight depending on population, tissue, season, water stress and whether the plant was grafted, so a single number for the species is meaningless. The table below lists each published measurement with its population or county, the tissue sampled, the growing condition, the sample size and the paper it came from. It is a reference for identification and taxonomy, and every row links to its source.

How long does Lophophora take to flower from seed?

A seed grown Lophophora williamsii reaches an identifiable 15 to 30 mm body between its fifth and eighth year, but its first flowers typically wait until somewhere between year ten and year twenty; a plant grafted onto fast rootstock can flower within three to five years instead. Wild plants take about ten years to mature. The widget below turns those published bands into a slider: pick an age and read the expected diameter and flowering likelihood for seed grown, grafted and wild plants. The bands stay bands on purpose; no source in the literature gives a single curve, and a plant kept dry and cool for a winter can sit at the same size for a year. For the provenance side of the wild column, the collector field numbers for Lophophora list every documented wild-collection record in our database.

Taxonomic history, 1839 to 2022

The genus has been renamed, split and lumped for nearly two centuries, and most of the names still sold on labels come from that history rather than from current taxonomy. Lemaire described the plant as Echinocactus williamsii in 1839; Coulter erected Lophophora in 1894; Croizat added L. diffusa in 1944; Habermann described L. fricii in 1975; and Bohata, Myšák and Šnicer added L. alberto-vojtechii in 2008 after its discovery the year before. The varietal names decipiens, texana, caespitosa and lutea all fall under L. williamsii today. Where the plants grow, and at what elevation, is mapped on where Lophophora grows in the wild, and the harvest record behind the conservation assessments is charted on the peyote harvest data page.

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