Obovate-cylindrical, 3 by 6 cm., simple: tubercles ovate, grooved
to the base, 5 to 6 mm. long, with woolly axils: radial spines 11
to 15, spreading, rather rigid and brownish (lighter with age), 8
to 10 mm. long; central spine much larger, 20 mm, long, hooked:
flower and fruit unknown. Type in Herb. Coulter.
San Luis Potosi.
Specimens examined: San Luis Potosi (Eschanzier of 1891).
++ Central spines 3 to 12.