Pringle 251 as distributed to Nat. Herb. is C. tuberculosus.
52. Cactus maculatus, sp. nov.
Obovate-cylindrical, 6 by 8 cm., somewhat cespitose: tubercles ovate, terete, 10 mm. long, grooved to the base, with naked axils: radial spines 10 or 11, straight and spreading, rigid, blackish (becoming ashy with age), black-tipped, 12 mm. long; central spine large, more or less spotted, erect, 25 to 35 mm. long: flower 13 mm. long, pinkish: fruit unknown. Type in Herb. Coulter.
San Luis Potosi.
Specimens examined: San Luis Potosi (Eschanzier of 1891).
Somewhat resembles C. tuberculosus in general appearance, but very different in spine characters.
53. Cactus brunneus, sp. nov.
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).