Taxonomy & identification

• Structural and developmental data indicate that Lophophora (family Cactaceae) should be retained as a distinct genus. [Structure, Development, and Taxonomy in the Genus Lophophora]
• The authors conclude that two species should be recognized within Lophophora: L. williamsii and L. diffusa. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Flowers originate at the summits of nascent tubercles near the center of the plant; perianth segments are thin, elliptical, mucronate, with entire or minutely ciliate margins. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Fruits are a pink-to-nearly-white, naked, dry-to-fleshy clavate berry that elongates rapidly above the surface and matures over several months, with seeds borne in the upper half. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Seeds are black and verrucose with a large flattened whitish hilum, vary from about 1.2-1.5 mm in length and 0.8-1.1 mm in width, and have a three-layered testa similar to that of Ariocarpus. [Structure, Development, and Taxonomy in the Genus Lophophora]
• The epidermis is papillose with a thick cuticle and glaucous (whitish) wax deposits, subtended by a hypodermis, and trichomes of the areolar tufts are mostly uniseriate. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Cortical cells contain numerous large druses (calcium oxalate crystal aggregates), and mucilage cells are abundant; Molisch's and Benedict's tests indicated reducing sugars in the mucilage. [Structure, Development, and Taxonomy in the Genus Lophophora]
• The genus Lophophora contains four species generally recognized as valid by Continental European systematists, with a fifth now also recognized (the paper notes 'four (now five!)' species). [Terry 2008 CSJ 80 part 1 (Lophophora taxonomy)]
• The genus authority/name is given as 'Lophophora Coulter' (referencing Bohata, Mysak & Snicer 2005, 'Genus Lophophora Coulter'). [Terry 2008 CSJ 80 part 1 (Lophophora taxonomy)]
• Diagnostic differences between L. koehresii and L. williamsii cannot be reliably discerned from desiccated herbarium specimens even by experienced experts; living plants must be observed in their natural ecological niches to appreciate the distinctions. [Stalking the wild Lophophora Part 3 (Cactus and Succulent Journal 2008, Volume 80, Number 6)]
• The article's conclusion: the genus Lophophora consists of three species — L. williamsii, L. diffusa (with var. koehresii), and L. fricii — plus possibly some forms. [Hansen 2000 — Lophophora fricii & williamsii var. decipiens]
• The genus Lophophora has two described species, L. williamsii and L. diffusa, both inhabiting desert areas and generally thriving on calcareous soils; the two are morphologically and chemically distinct. [Conservation Status, Germination, and Establishment of the Divine Cactus, Lophophora williamsii (Lem. ex Salm-Dyck) J. M. Coult., at Cuatro Ciénegas]
• How many species Lophophora contains is genuinely unsettled - taxonomists disagree, and the counts cited here reflect competing expert classifications rather than a single agreed answer. [Cactus Codex editorial summary]

Phylogenetics — the DNA story

• Lophophora appears to be most closely related to Thelocactus (sensu lato). [Structure, Development, and Taxonomy in the Genus Lophophora]
• Externally the flowers of Lophophora are similar to those of Ariocarpus, Turbinicarpus, Pelecyphora, Astrophytum, Thelocactus, Toumeya, Echinocactus, Strombocactus, Obregonia, and Leuchtenbergia, indicating relationships among these genera. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Some species of Thelocactus and Toumeya have ovaries with only a few scales, approaching the nearly naked ovary condition of Lophophora, suggesting a transition toward nakedness. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Buxbaum placed Lophophora among his 'Strombocacti,' a grouping that also included genera such as Strombocactus, Obregonia, Leuchtenbergia, Ariocarpus, Aztekium, Pelecyphora, Epithelantha, Toumeya, and Echinomastus. [Structure, Development, and Taxonomy in the Genus Lophophora]
• The diploid chromosome number of Lophophora is 22, determined from root tips of both northern and southern populations, with no polyploidy detected. [Structure, Development, and Taxonomy in the Genus Lophophora]
• At the time of the trip no thorough molecular systematics study of the genus existed; the authors collected tissue samples to extract DNA intending to produce the first thorough study of the molecular systematics of Lophophora. [Terry 2008 CSJ 80 part 1 (Lophophora taxonomy)]
• The study collected tissue samples from multiple populations of L. williamsii, L. koehresii, and L. diffusa for a DNA/phylogenetic study; DNA was extracted at the Instituto de Biologia, UNAM, in the lab of Hector Hernandez, with results intended for later publication in Haseltonia. [Stalking the wild Lophophora Part 3 (Cactus and Succulent Journal 2008, Volume 80, Number 6)]

Native range

• The genus occupies two major geographically separated populations: an extensive northern population and a restricted southern population. [Structure, Development, and Taxonomy in the Genus Lophophora]
• No Lophophora population has been located in Chihuahua state by university researchers there; the only Chihuahuan Lophophora locality in the UNAM herbarium database was near Julimes (west toward the Sierra de la Amargosa), but at the GPS site all plants had been poached out. [Terry 2008 CSJ 80 part 1 (Lophophora taxonomy)]

Habitat

• Lophophora is a highly xerophytic member of the Cactaceae, with stems whose photosynthetic palisade tissue and water-storage mucilage system reflect adaptation to arid habitats. [Structure, Development, and Taxonomy in the Genus Lophophora]

Growing & propagation

• Seedlings are globose and bear three to six vestigial leaves; distinct tubercles and podaria develop later, with much variation between six and eight months of age. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Cactus growers in many countries (including British growers) are permitted to grow peyote, which is frequently listed on seed lists of sister societies and foreign nurseries; however, peyote has been banned in France, Italy, the Czech Republic, Russia, Poland, and (most recently) Australia. [Stalking the wild Lophophora Part 3 (Cactus and Succulent Journal 2008, Volume 80, Number 6)]

History

• The plant was first described as a species of Echinocactus, named Echinocactus williamsii. [Structure, Development, and Taxonomy in the Genus Lophophora]
• The genus Lophophora itself was established by John Merle Coulter in 1894 (Contributions from the U.S. National Herbarium 3: 131); the standard author abbreviation is 'J.M.Coult.' [POWO/IPNI 5395-1]
• An illustration of the species first appeared in Curtis's Botanical Magazine in 1847. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Thompson (1898) reviewed the species of cacti commonly cultivated under the generic name Anhalonium. [Structure, Development, and Taxonomy in the Genus Lophophora]
• Croizat (1943-45) published a study of the genus Lophophora in Desert Plant Life. [Structure, Development, and Taxonomy in the Genus Lophophora]
• The fieldwork was a Cactus Conservation Institute project involving Martin Terry with students Robert Hibbitts and Lia (Rozalia) Carrasco and colleagues Keeper Trout and Bennie Williams, funded by a grant from the Research Committee of the Cactus and Succulent Society of America and a Research Enhancement grant from Sul Ross State University; the work built on the foundational efforts of Ted Anderson and Richard (Dick) Schultes. [Stalking the wild Lophophora Part 3 (Cactus and Succulent Journal 2008, Volume 80, Number 6)]