Xerophyte

Central Spines

Solitary, rarely as many as 4, sometimes absent, more or less curved or hooked, 1 to 2 cm long light brown.

Seeds

Spherical to ellipsoid, slightly constricted above the hilum, black, whit no aril.

Flowers

Inodorous, borne laterally, open during the day, pink to red, mediumto long tubed (ca 9 cm). Outer perianth-segments, linear, acuminate. Inner perianth-segments, oblong, acute. Scales of pericarpel and tube with axillary hairs. They are mainly pollinated by solitary bees.

Ribs

15-16(-20), stout, 1 cm high, broad at base, somewhat crenate, divided into many small tubercles.

Stem

Simple, subglobose, depressed, to 8(-10) cm in diameter ( up to 10 cm high in cultivation. Grown from seed.), shining dark green.

Radial Spines

3 to 7(-10), whitish, slender, flexible, spreading backward, 5 to 15 mm long.

Fruits

Ellipsoid, dirty green to greenish purple, somewhat dry, 16 mm long, 8 mm in diameter. Scales on ovary and flower-tube small, their axils lanate.