Xerophyte

Central Spines

Solitary, stouter than the radials, standing out at right angle to stem, 2 to 3.5 cm long.

Flowers

As the species, red, but smaller only 1.2-5 cm long, remaining open for several days. Petals short, blunt. Ovary tube almost without no wool, with clusters of 2-6 slender spines up to 12 mm long. Stigma lobe 5 to 8 light green.

Spines

Rigid, round, straight, with very bulbous bases, yellowish to greyish brown, often with red streaks and shadings, especially toward bases.

Ribs

7 to 9, obtuse, shallow, somewhat tubercled, only slight cross-furrows between areoles.

Stem

Globular, ovoid, or cylindrical, loosely clustered, bright green or yellowish green, plump, with shiny surfaces 7 to 10(-12.5) cm long in northern range, 22-30 cm in southern part, 5 to 7(-12) cm in diameter.

Radial Spines

(3-)7 or 8(-9), 10 to 24(-35) mm. Long.

Fruits

Round, smooth, red, 12-18 mm in diameter; naked when ripe.

Areoles

Round, when young white-woolly, about 4-5 mm across, 8 to 16(-40) mm apart, in age naked and entirely filled by swollen bases of spines.