This variety is easily recognized by the very dark olive-green body and
the strong, more numerous, longer, overlapping, spines that are white
with a darker base.
Description: Solitary cactus. Usually larger
than the typical gibbosum.
Stem: Deep olive-green to almost black, flat to almost
spherical, 3-5(-10) cm tall, up to 12 cm in diameter, the apex is
Ribs: 10-16 straight, divided in well distinct, angular ribs.
Radial spines: 7-10 (-12) 25-35 mm, strong, long, erect,
overlapping, pastel-white (but also yellow or black), with a darker
(reddish or brownish) base when young, that becomes whitish-grey as they
Central spines: 0-2 very similar to the radials.
in the nearest periphery just around the apex, 45-60 mm
long, 60-65 in diameter.
Tepals ivory white with a brownish mid rib or
Blooming season: Will flower without a distinct
mm long green with white bordered scale.
The density of spines is quite variable from one individual to another.
This plant is a summer
grower and pretty easy to cultivate. Water and fertilize moderately in
summer. It requires excellent drainage. Make sure that soil gets the
chance to dry out in between waterings. During cold weather periods
keep rather dry, but it can handle excessive water to little water.
for half-shade but it grows well in full sun and full shade, too (but in
full sun it turns an uneven brownish red colour).
Frost Tolerance: Hardy down to -12° to -32° C.
Propagation: Mainly through seeds.