Xerophyte

Habit

Simple at first later usually clustering, the plants may form large clumps developing offsets on stolons which may emerge up to 20 cm away from the parent plant,

Central Spines

1-6, sometimes difficult to distinguish from radials, yellowish, pale to dark brown, light rose, reddish brown or black, 8-40 mm long tending to point downward.

Seeds

15-100 per fruit. Bell-shaped glossy black, 1,2-1,4 long and 11,7-1,2 mm broad strongly tuberculate.

Flowers

3,5-6 cm in diameter, few often closely packed apically, bright satiny yellow in one rare variant orange-red, pericarpels and tube with dense white to brownish wool and bristles. Stigma-lobes usually red or purplish, rarely orange or yellow.

Spines

Slender hair-like, straight, curved or twisted, relatively sparse that does not hide the epidermis.

Ribs

6-12, rarely up to15, well defined. rounded or acute.

Stem

More or less spherical, tapered at base, eventually cylindrical with a flattened top, 2-15 cm in diameter (mostly less than 10 cm), light. Deep-green, bluish green, and can get deep purplish to maroon during winter dormancy, though this colour can be retained if grown in sufficient light. However the new growth is green but will soon darken to match the older epidermis.

Radial Spines

4-15 spreading radially, with a starlike appearance, whitish, yellow, pale rose or brown. 5-30 mm long.

Fruits

Ovoid to short oblong. 9-12 mm in diameter green, not elongating at maturity, thin to thick-walled. dehiscent lengthwise to expose the seeds and white pulp.