Cochemiea is a genus of cacti in the family Cactaceae (order Caryophyllales), native to the arid regions of the southwestern United States and Mexico. The genus was originally described as a subgenus of Mammillaria by American botanist Mary Katharine Brandegee in 1897, then elevated to genus rank by British botanist Frederick Arthur Walton in 1899. For much of the 20th century it was re-synonymized with Mammillaria, but a 2021 molecular phylogenetic study of the "mammilloid clade" by Breslin, Wojciechowski, and Majure demonstrated that Mammillaria in its broad sense is not monophyletic, and Cochemiea was re-established as a distinct genus encompassing a substantially expanded set of species formerly placed in Mammillaria, Neolloydia, Neomammillaria, and Ortegocactus.
Plants in the genus are characterized by elongated, cylindrical stems ranging from 3 to 7 cm in diameter and typically 7 to 50 cm in height, though exceptional individuals may reach 200 cm. The stems are green to bluish-green and covered in spirally arranged tubercles. Each areole bears 7 to 25 radial spines (1–2 cm long, white to reddish-brown) and 1 to 6 central spines (occasionally up to 11), which may be white-tipped black, reddish-brown, or fully black. The flowers are zygomorphic, 3 to 5 cm long, typically red or purple, and emerge in two rows from the axils near the stem apex. Fruit is spherical and indehiscent with a smooth surface; seeds are black and minute (0.5–1 mm).
Etymology
The genus name Cochemiea honors the Cochimí, an indigenous people who historically inhabited Baja California — a region within the natural distribution of the plants. The Cochimí are now considered an extinct distinct cultural and linguistic group.
Distribution
Cochemiea occurs across the southwestern and south-central United States — Arizona, California, Nevada, New Mexico, Texas, and Utah — and extends into Mexico, including Mexican Pacific Islands and the Gulf of Mexico coastal region. Plants grow in rocky cliffs, canyons, and scrubland, tolerating both full sun and shrub shade, at elevations up to 1,800 m above sea level.
Taxonomy Notes
Cochemiea was first described by Mary Katharine Brandegee in 1897 as a subgenus of Mammillaria, then elevated to genus rank by Frederick Arthur Walton in 1899 (Cactus Journal 2: 50). It was subsequently lumped back into Mammillaria for most of the 20th century. A 2021 molecular phylogenetic analysis of the mammilloid clade (Breslin, Wojciechowski & Majure) resolved four distinct monophyletic groups, re-circumscribing Cochemiea as an expanded genus that absorbs many former Mammillaria species as well as Neolloydia conoidea. Plants of the World Online accepts this expanded circumscription as of January 2026.
