Una especie nueva de Strombocactus (Cactaceae) del río Moctezuma, Querétaro, México A new species of Strombocactus (Cactaceae) from Moctezuma River, Querétaro, Mexico

Strombocactus corregidorae S. Arias et E. Sanchez, from the Infiernillo Canyon, in the Moctezuma River, at the border between the Mexican states of Queretaro and Hidalgo, is described and illustrated. It differs from S. disciformis by its massive body, larger, strong, thick, persistent, black-gray spines, yellow flower, seeds with flat periclinal wall cells, finely reticulate micro-relief, and hilum-micropylar region not covered by a strophiole. An identification key to Strombocactus species, based on stem, flower, and seed characters is included.