Described in this Journal in 1979 by L. Bremer (vol. 51,2:76 - 77), this northern Mexican species is said to be allied to the more central Mexican C. cornifera (ISI 2013-1). It differs in its more napiform rootstock and smaller tubercles making for a more densely-spined plant. Central spines (when present) are darker than the tan radials (though all age gray). The species was originally described as lacking central spines but that has since been amended so C. palmeri and C. jaumavei are now included as synonyms. The flowers are satiny light yellow creating cheerful parasols over the body when fully open and may repeat several times during early summer. HBG 126091, from seed from controlled pollination of plants originally collected along the south side of Mexican Hwy 40 between Monterrey and Saltillo in Coahuila, Mexico, an area where the species is widespread. $7.