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.