Mamillaria gabbii Engelm Mss.
Globose, 5 to 10 cm. in diameter, simple: tubercles cylindrical,
slender, 12 to 14 mm. long, with woolly axils: radial spines
about 13, 5 to 8 mm. long, lower ones longer and stouter,
especially the lateral ones pectinate; the central shorter,
straight, and robust: flowers small, yellowish-red: fruit
unknown. Type in Herb. Mo. Bot. Gard.
Among rocks, from San Ignacio to Mission San Fernando, Lower
California, and "perhaps farther north in the interior."
Specimens examined: Lower California (W. M. Gabb 19 of 1867).