Always grows solitarily. It is a variable
low growing species especially for spination. (Some plants have minimal
spination while others seem quite heavily armed)
green, dull olive-green
to brownish, flattish globular (mature plants may become slightly short
columnar) 7-15(-20) cm across, with a somewhat sunken apex.
Ribs: Usually 7-12 (up to 16) , very flat and broad, with
scarcely evident protuberances and often a small horizontal indention
above the areoles.
Areoles: Covered by some tomentum.
Spines: Stout, awl shaped,
glassy white to light-brown in clusters of about 7 mostly straight up
to10-30(-60) mm in length, very symetrical, and tending to curve
upwards, away from the body of the cactus.. no obvious central spine.
The 1 or 2 central spines - when one exists - have the same length.
Flowers: Mostly near the apex,
bell-shaped, pure white or white with a hint of lilac, about 30 mm in length and
diameter. Inner petals are white to light pink, outer petals are a light
purple colour with a dark purple centre strip. Filaments and style are
white. Anthers creamy-white to pale yellow.
Blooming season: Flowers freely
throughout the Summer.
Fruit: Round or barrel shaped, about 20 mm in diameter, red with
scales of the same colour, fruits are juicy and of a carmine colour.
Seeds: Almost nodular, yellowish brown with very fine
protuberances, about 0,7 mm in length, white hilum, long and thin.