Xerophyte

Central Spines

None, but occasionally after several years develop the central spines, giving the plant its sea urchin appearance.

Tubercles

Closely set in about 13 rows but not very regularly arranged, pale green, not very flaccid.

Flowers

Pale yellow to nearly white flowers up to 5 cm diameter.

Stem

Globular small, somewhat depressed, pale grey-green to deep green, 4-5 cm high, 6-8 cm broad, but occasionally up to 10 cm tall and clustered especially in cultivation.

Radial Spines

11 to 14, rather stout, horizontally radiating nearly at right angles to central one, yellowish with tips often blackish.