Xerophyte

Seeds

Seed oval to broadly oval, reddish to dark brown or nearly black, 1-1.6 mm black with conspicuous pale hilum.

Flowers

Funnel-shaped to 4-6 cm long, 3.5 cm white with deep pink throat. Pericarpel 1-2 cm long, 5-7 mm in diameter; pericarpel scales with light margin and sometimes pinkish tip. Perianth segments numerous, rounded, truncate, cuspidate or apiculate. Style whitish, with pale yellow stigma 20-35 mm long. Stamens purple-pinkish, to whitish at the apex, pollen straw-coloured. The form of the perianth segments is highly variable between populations and the form of the flower - broad or slender – is also varied. Most plants are dioecious and autosterile.

Spines

5-11(-13) but Backeberg (1959) mentioned up to 20 spines per areole, these are up to 2.5 (or more) cm long, curved towards the body or prominent, not clearly differentiated into centrals and radials. Bristle-like, yellowish at first, later greyish.

Ribs

5 to 13 (usually 6-8), rounded, with no or little undulation from tubercles on vertical clefts and tubercles not clearly defined (furrow on the rib between areoles absent).

Stem

Flat-globular to globular (during the dry season sometimes sunken into the soil) 4-10 cm in diameter, often more or less cylindric in cultivation. Epidermis dark glossy green.

Fruits

Almost spherical to club-shaped 1.5-4 cm long, softening but not splitting when ripe, and dissolves when touched, light to dark green, sometimes bluish (colour depends on the amount of epidermal wax).

Areoles

Approximately circular with white to pale brownish wool.