Encyclopedia

Complete guide to the genus Geohintonia. The monotypic gypsum-cliff endemic of Galeana, Nuevo Leon: 1 species, magenta flowers, and a substrate that rejects limestone entirely.

Pelecyphora aselliformis is the woodlouse cactus of San Luis Potosi, Mexico; paired pectinate spine ranks on flattened axe-blade tubercles, magenta to violet-pink apical flowers, IUCN Least Concern, CITES Appendix I. Cactaceae.

Pelecyphora strobiliformis is the pinecone cactus of Tamaulipas, Nuevo León, and San Luis Potosí; imbricate triangular tubercles stacked like a spruce cone, magenta apical flowers. IUCN Least Concern. CITES App I. Cactaceae.

Obregonia denegrii is the artichoke cactus of the Jaumave Valley, Tamaulipas; flat-rosette of overlapping triangular tubercles, CITES Appendix I, IUCN Endangered 2013. Monotypic genus. Cactaceae.

Strombocactus disciformis is the disc cactus of the Moctezuma Canyon, Hidalgo; a flattened-disc lithophyte with 13:8 Fibonacci spiral tubercles, cream flowers with a magenta midvein, and 8-10 years to first bloom from seed. IUCN Vulnerable. CITES Appendix I. Cactaceae.

Complete guide to the genus Pelecyphora. The rarest miniature cacti of the Chihuahuan Desert: 2 species, CITES Appendix I, pectinate woodlouse spines, and apical magenta flowers.

Complete guide to the genus Obregonia. The artichoke cactus of the Jaumave Valley, Tamaulipas: 1 species, CITES Appendix I, IUCN Endangered, and one of the most visually distinctive cacti in cultivation.

Complete guide to the genus Strombocactus. Two CITES Appendix I lithophytes from Mexico’s calcareous canyon systems: the classic disc cactus and its newly described canyon-wall sibling.

Complete guide to the genus Leuchtenbergia. The agave cactus of the Mexican Plateau: 1 species, the most agave-like silhouette in Cactaceae, and large fragrant yellow flowers on pencil tubercles.

Coryphantha tripugionacantha is Alfred Lau’s Zacatecas dagger-spine cory: three projecting black centrals per areole, solitary grey-green body to 9 cm, pale yellow apical flowers. CITES Appendix II, IUCN Least Concern.