Mammillaria

Known Species

Mammillaria napinaMammillaria napina→Tehuacán-Cuicatlán geophyte with a tuberous taproot and pink apical flowers over pectinate white spines.Mammillaria pectiniferaMammillaria pectinifera→Tehuacán Valley miniature on the same limestone as napina; 18 fragmented Puebla localities.Mammillaria schwarziiMammillaria schwarzii→Single volcanic-cliff population in northern Guanajuato; glassy white spine mat obscures the 3 cm heads.Mammillaria duweiMammillaria duwei→Guanajuato endemic near San Luis de la Paz; ~500 individuals with plumose feathery white spines.Mammillaria herreraeMammillaria herrerae→Single-location Querétaro endemic wrapped in 100+ white bristles with disproportionately large pink flowers.Mammillaria herrerae f. albifloraMammillaria herrerae f. albiflora→White-flowered form of herrerae; known only from the same single Querétaro cliff as the type.Mammillaria luethyiMammillaria luethyi→Rediscovered 1996 after 44 years; pectinate spines and pale violet flowers on a clustering body.Mammillaria huitzilopochtliMammillaria huitzilopochtli→Oaxaca endemic named for the Aztec war god; aggressive hooked central spines.Mammillaria bertholdiiMammillaria bertholdii→Described 2016 from a single Oaxaca locality; fewer than 2,000 individuals with hooked central spines.Mammillaria crucigeraMammillaria crucigera→Cross-shaped areole spines; two subspecies, both restricted to the Oaxaca-Puebla border.

What is Mammillaria, the pincushion cactus?

Mammillaria is the largest genus in the family Cactaceae, comprising 143 accepted species under the current Kew POWO circumscription (Breslin et al. 2021), all characterized by conical or cylindrical tubercles arranged in Fibonacci spirals rather than continuous ribs. The common name “pincushion cactus” refers to both Mammillaria and the closely related Escobaria, though Mammillaria is the far larger group.

Where does Mammillaria grow in the wild?

Approximately 98% of accepted species are native to Mexico, with the Tehucán-Cuicatlán Valley and the Chihuahuan Desert holding the highest density. The genus reaches into the Sonoran and Chihuahuan deserts of the southwestern United States and south to Colombia and Venezuela. Endemism within Mexico runs at roughly 88%, meaning almost nine in ten species occur nowhere else on Earth.

What are pectinate spines, and which Mammillaria species have them?

Pectinate spines are radial spines arranged in flat, comb-like rows pressed tight against the tubercle surface, completely obscuring the plant body beneath interlocking white spine-fans. The feature appears in some of the most sought-after collector species: Mammillaria pectinifera, which carries 40 or more white radial spines per areole; M. perezdelarosae subsp. andersoniana, with 50 to 63 pectinate radials per tubercle; and M. bertholdii, described from Oaxaca in 2014.

How do Mammillaria flowers form their characteristic ring?

Mammillaria flowers emerge from the axils of tubercles formed during the previous growing season, not from the current year’s growth apex, producing a ring or halo of blooms encircling the upper third of the stem. This ring-forming mechanism is taxonomically diagnostic: it separates Mammillaria from Coryphantha, whose flowers emerge at the growing point.

How fast does rare Mammillaria grow from seed?

Common species can reach first bloom in 2 to 3 years. Rare pectinate-spine species are a different timeline: seed grown M. herrerae typically requires 8 to 12 years to reach flowering size. Grafting accelerates that to under two years but produces plants that never settle into the flat-globose habit that seed grown plants maintain.

Which Mammillaria species are the most endangered?

Several species are assessed as Critically Endangered by the IUCN. Mammillaria duwei has an area of occupancy of just 35 km² and is known from one location in Mexico. M. perezdelarosae subsp. andersoniana is estimated at fewer than 1,000 individuals in 1,000 m² of habitat in Zacatecas. M. herrerae numbers only a few hundred in the wild, with very low seedling recruitment.

Are Mammillaria species protected under CITES?

The entire Cactaceae family has been listed on CITES Appendix II since 1975, requiring valid export permits and documentation confirming specimens were not taken illegally. A handful of Mammillaria species, including M. pectinifera and M. solisioides, carry the stricter Appendix I listing, which prohibits commercial international trade. Within Mexico, the most threatened species receive additional protection under NOM-059-SEMARNAT-2010.

How should rare Mammillaria be cultivated?

Rare pectinate-spine species grow in mineral-poor substrates on calcareous or igneous rock faces at 1,900 to 2,300 m elevation. A substrate of 70 to 80% inorganic mineral material (pumice, decomposed granite, or lava rock) mixed with a small fraction of low-nutrient organic material replicates those conditions. Water thoroughly during the growing season only when the substrate has dried completely; in winter, a full dry rest at cool temperatures triggers the spring flowering flush.